Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/245—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it being a foam layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/08—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers
  • B29C70/081—Combinations of fibres of continuous or substantial length and short fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/08—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers
  • B29C70/086—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers and with one or more layers of pure plastics material, e.g. foam layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/20—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres
  • B29C70/205—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres the structure being shaped to form a three-dimensional configuration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/20—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres
  • B29C70/205—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres the structure being shaped to form a three-dimensional configuration
  • B29C70/207—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres the structure being shaped to form a three-dimensional configuration arranged in parallel planes of fibres crossing at substantial angles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/22—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure
  • B29C70/222—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure the structure being shaped to form a three dimensional configuration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/22—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure
  • B29C70/226—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure the structure comprising mainly parallel filaments interconnected by a small number of cross threads
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/24—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least three directions forming a three dimensional structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/88—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced
  • B29C70/882—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced partly or totally electrically conductive, e.g. for EMI shielding
  • B29C70/885—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced partly or totally electrically conductive, e.g. for EMI shielding with incorporated metallic wires, nets, films or plates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/10—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material
  • B32B3/12—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/024—Woven fabric
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/12—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
  • B32B5/262—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary characterised by one fibrous or filamentary layer being a woven fabric layer
  • B32B5/263—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary characterised by one fibrous or filamentary layer being a woven fabric layer next to one or more woven fabric layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/02—Synthetic macromolecular fibres
  • B32B2262/0253—Polyolefin fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/02—Synthetic macromolecular fibres
  • B32B2262/0261—Polyamide fibres
  • B32B2262/0269—Aromatic polyamide fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/10—Inorganic fibres
  • B32B2262/101—Glass fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/10—Inorganic fibres
  • B32B2262/106—Carbon fibres, e.g. graphite fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2266/00—Composition of foam
  • B32B2266/02—Organic
  • B32B2266/0214—Materials belonging to B32B27/00
  • B32B2266/0221—Vinyl resin
  • B32B2266/0235—Vinyl halide, e.g. PVC, PVDC, PVF, PVDF
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/558—Impact strength, toughness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/718—Weight, e.g. weight per square meter
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2603/00—Vanes, blades, propellers, rotors with blades
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2605/00—Vehicles

Definitions

• the present disclosure relates to shock and impact resistant structures. Particularly, the present disclosure is directed to embodiments of materials having a helicoidal architecture.
• U.S. Patent No. 6,641,893 and U.S. Patent No. 9,452,587 each of which is hereby incorporated by reference herein in their entirety, describe a fiber reinforced elastic composite ply stacking approach in which the individual layers are rotated along the longitudinal or x-y axis at a predefined angle relative to the adjacent layers so as to create a z-direction helicoidal fiber oriented stack (i.e. laminate).
• This helicoidal clocking can be chosen to create a specific spiraling pitch or circular polarization.
• the spiral formed from the assembly of these pitched fibers can be tuned to a specific wavelength to dampen propagating shock waves initiated by ballistics, strike forces or foreign material impacts; can have matrix additives to toughen and arrest propagation of catastrophic fractures; and can be made to exploit the difference in elastic moduli between the fibers and matrix resin to further arrest fractures generated from blunt or sharp impacts.
• This disclosure describes details for designing and manufacturing shock and impact resistant structures from thin ply uni-directional (TPUD), thin-ply woven fabrics (TPW), quasiuni-directional woven fabrics (QUDW) and hybrid fiber reinforced helicoidal materials, arranged, for example, as stacks of polymer based composite material. Also described are apparatuses that include the envisioned structures: consumer products, protective armor, sporting equipment, crash protection devices, wind turbine blades, cryogenic tanks, automotive/aerospace components, construction materials, and other composite products.
• TPUD thin ply uni-directional
• TPW thin-ply woven fabrics
• QUDW quasiuni-directional woven fabrics
• hybrid fiber reinforced helicoidal materials arranged, for example, as stacks of polymer based composite material.
• apparatuses that include the envisioned structures: consumer products, protective armor, sporting equipment, crash protection devices, wind turbine blades, cryogenic tanks, automotive/aerospace components, construction materials, and other composite products.
• Fig. 1 is an illustration of an example of a helicoidal geometry.
• Figs. 2A-2B illustrate examples of a matrix resin molecular structure.
• Fig. 3 illustrates a stack of fiber layers arranged into a helicoidal pattern according to embodiments of the invention.
• Figs 4A-4B illustrate discontinuous and continuous material forms.
• Figs. 5A-5H illustrate uni-directional and other material forms.
• Fig. 6 illustrates fiber crimping arising from interlacing.
• Fig. 7A illustrates a helicoidal preform made of straight fiber placement on a 3D curved shape according to embodiments of the invention.
• Fig. 7B illustrates a helicoidal preform made of curved fiber placement on a 2D shape according to embodiments of the invention.
• Fig. 8 is an illustration of an MX fabric machine.
• Fig. 9 is an illustration of a fiber metal laminate.
• Figs. 10A-10B are illustrations of composite sandwich structures.
• Fig. 11 depicts an illustration of a helicoidal laminate stack.
• Fig. 12 depicts laminate intra and interlaminar zones.
• Fig. 13 depicts examples of individual fiber interlaminar contact lengths according to embodiments of the invention.
• Figs. 14A-14C depict typical composite impact damage.
• Figs. 15A-15C depict typical composites where nanomaterials bridge gaps and cracks between fibers.
• Fig. 16 depicts a stairstep shaped clocking spiral assembly according to embodiments of the invention.
• Fig. 17 depicts an illustration of fiber placement steering.
• Figs. 18A-C are schematic views of a structure that includes both impact resistance and load carrying strength according to embodiments of the invention.
• Fig. 19 shows a spread tow woven fabric and a light-tow woven fabric.
• Figs. 20A-C show initial crack formation in woven fabric composites according to embodiments of the invention.
• Figs. 21A-C show QUDW fabric according to embodiments of the invention.
• Figs. 22A-B show QUDW fabrics with different included angles between plies according to embodiments of the invention.
• Fig. 23A shows the ply orientations of a helicoidal layup according to embodiments of the invention.
• Fig. 23B shows the ply orientations of a conventional thin-ply biaxial layup.
• Fig. 24 shows force vs. displacement for various plies and arrangements according to embodiments of the invention.
• helicoidal refers to a stacking arrangement of plies of fibers wherein the fibers of at least one ply define an orientation direction relative to an orientation direction of the fibers of an adjacent ply and that provide an included angle greater than 0° and less than about 30°.
• the stacking arrangement may include adjacent plies that define included angles outside of this range, and the stacking arrangement may comprise less than a full rotation of 360°, or may comprise more than one full rotation.
• the fiber orientation direction of one or more plies may be straight or curved.
• novel enhancements set forth herein include helicoidal materials including: (a) nanomaterials, (b) variable pitch and partial spirals, (c) TPUD lay-ups, (d) hybrid materials, (e) curved fibers within a ply, (f) automated fiber or tape or patch placement for 2D or 3D preforms, (g) non-crimped fabrics, (h) 3D woven fabrics, (i) 3D printed materials, and (j) filament wound materials, (1) TPW layups, (m) QUDW layups.
• helicoidal materials can be laid up by hand, direct placed with automated machines, and/or pre-assembled in stacks using weaving/braiding/stitching equipment (e.g., non-crimp fabric machines).
• Additive (e.g., 3D printing) manufacturing techniques can be used to vary and mix material types. For example, polymeric and metallic fibers can be used together that are printed using additive manufacturing techniques in building the helicoidal stack.
• Impact behavior of composite structures is a complex dynamic phenomenon that can involve elastic deformation, matrix resin cracking, fiber breakage and eventually intra-ply and/or inter-ply delamination. Component failure can occur at free edges, areas of concentrated bearing load or at the point of maximum stress induced by a foreign object impact. Impact damage is often worse on the side opposite the strike and can go visually unnoticed, requiring extensive non-destructive inspection (e.g., hand-held ultrasonics). Therefore, impact resistance and damage tolerance are often design limiting criteria. Impact damage can reduce, or limit inplane load carrying capability and require a product to be removed from usage for repair or if the damage is extensive scrapped and replaced.
• Resin materials The molecular structure of matrix resin in a composite consists of a backbone structure (polymer chain) with numerous and varying types of cross-links (i.e., network structures), See Figs. 2A-B.
• Traditional thermosets compositions that go through a phase change curing reaction to reach final form typically possess rigid, highly cross-linked, glassy polymeric structures. This molecular arrangement can make a composite susceptible to matrix cracking and/or delamination when impacted.
• thermoplastic resin one that melts instead of cures and typically has a higher molecular weight and lower degree of cross-linking and/or is more amorphous than crystalline
• toughening of the thermoset resin via network alteration e.g., lowering monomer functionality, increasing the backbone molecular weight, or incorporation of flexible subgroups
• elastomer toughening by introducing discrete rubber or thermoplastic particles
• interlayer toughening incorpororation of a thin thermoplastic veil, typically 0.001 in) between thermoset plies.
• Resin toughening is well known and utilized in the industry.
• Embodiments of the invention may also use vitrimers, which are reprocessable thermoset resins, in addition to or in replacement of nonreprocessable thermoset or thermoplastic resins.
• microspheres and micropores into a helicoidal laminate, such as in the fiber structure illustrated in Fig. 3, is used in composite materials.
• nanovoids e.g., formed by a laser or other mechanism
• voids or regions of weakness can be provided with a directional component so as to cause catastrophic failure to occur in a preferred location and/or along a preferred direction.
• Voids can have any desired average dimension (an average transverse dimension) between, for example, 0.1 nanometers and 500 microns, or any increment therebetween of 0.1 nanometers, or any subrange within that range having an extent between 10 nanometers and 50 microns, such as a subrange of 10 nanometers, 25 nanometers, 50 nanometers, 80 nanometers, 100 nanometers, 150 nanometers, 250 nanometers, 500 nanometers, and so on.
• average transverse dimension between, for example, 0.1 nanometers and 500 microns, or any increment therebetween of 0.1 nanometers, or any subrange within that range having an extent between 10 nanometers and 50 microns, such as a subrange of 10 nanometers, 25 nanometers, 50 nanometers, 80 nanometers, 100 nanometers, 150 nanometers, 250 nanometers, 500 nanometers, and so on.
• Nanomaterials Incorporation of nanoparticles [e.g., carbon nanotubes (CNTs) and graphene] or elongated nanofibers, such as in the form fibers having an average diameter less than 100 nm, into a matrix resin which can also be combined with fiber reinforcements can improve mechanical properties and impact resistance over conventional composite laminates of identical thickness. This improvement can sometimes be attributed to whiskering (i.e., nanoscale whiskers interacting with the fibers to improve transverse and intralaminar shear properties).
• CNTs carbon nanotubes
• graphene elongated nanofibers, such as in the form fibers having an average diameter less than 100 nm
• Fibers provide a composite with strength and stiffness. Fibers can be continuous or discontinuous, depending on the application and manufacturing process. Fibers can also be tailored (arranged in preferential orientations to suit the given application). Most prevalent in the industry, plies are clocked every 45 degrees using 0, +45, -45, and 90-degree orientations. The type and amount of fiber reinforcement in a composite can be varied for cost, manufacturing and performance reasons. Certain fiber types (i.e., carbon and graphite) are high in specific strength (properties like tensile and compression divided by density), but are inherently brittle while others, like fiberglass, have better impact strength but lower specific strength due to higher density.
• Aramid (an aromatic polyamide) fibers have excellent toughness and outstanding ballistic and impact resistance, but have reduced performance with temperature fluctuation, are susceptible to ultraviolet light, and tend to absorb moisture.
• a wide variety of known fiber types can be used to make helicoidal structures, such as carbon, fiberglass, aramid, basalt, ultra-high molecular weight polyethylene (UHMWPE), ultra-high molecular weight polypropylene (UHMWPP) (e.g., Innegra®), selfreinforced polymeric fibers (e.g. Pure®, Tegris®, Curv®), natural fibers such as flax or hemp, metallic fibers, quartz fibers, ceramic fibers and recycled fibers of any of these types.
• UHMWPE ultra-high molecular weight polyethylene
• UHMWPP ultra-high molecular weight polypropylene
• selfreinforced polymeric fibers e.g. Pure®, Tegris®, Curv®
• natural fibers such as flax or hemp, metallic fibers,
• Material forms Like resin and fiber selection, material form is generally driven by application, cost and manufacturing process. Broadly speaking, material form can include discontinuous or continuous fibers with random or oriented directionality as illustrated in Figs. 4 A and 4B.
• Continuous/oriented fiber forms in general have superior structural properties but are more costly to fabricate requiring manual or specialized methods (automated material placement (AMP) or weaving, braiding, ply stitching, 3D printing or winding equipment) versus plastic injection and compression molding of sheet molding compounds, prevalent with discontinuous fiber form manufacture.
• Two main categories of continuous material formation are uni-directional (UD) and woven (including 3D weaving & braiding).
• Fig. 5 A illustrates uni-directional manufacturing
• Fig. 5B illustrates a woven structure.
• Fig. 5C presents an example of non-crimped multi-axial fabric
• Fig. 5D presents a net-shaped preform.
• Fig. 5E presents a schematic of a 3D woven fabric
• Fig. 5F presents an example of filament winding
• Fig. 5G presents an example of fiber patch placement
• Fig. 5H presents an example of braiding.
• UD tapes in general provide better in-plane structural properties than woven fabrics due to the absence of fiber crimp (fibers being taken in and out of plain during interlacing), see Figure 6. It will be appreciated that the figures are not necessarily to scale. Weaving can create z-direction fibers and interlocked non-planar fiber bundles that spread point loads and slow or arrest matrix cracking and laminate delamination. But weaving requires large complex machinery, hence the cost can be high and size limited. Further, in-plane properties are typically reduced due to fiber crimping when compared to UD composites. Transverse stitching has been used with UD composites to create z-direction load carrying capability and as a crack arrestor.
• the current disclosure extends the helicoidal application/design to include specific materials (most prevalently TPUD tape, TPW and QUDW), as well as glass, carbon, aramid fibers, and the like, as well as novel fiber angle clocking combinations to help to overcome drawbacks and limitations of current impact resistant composite designs, as well as skins in sandwich applications where helicoid layups have never been explored due to the lack of design space to reproduce full helicoidal stacks.
• AMP is an exemplary low-cost method for placing them.
• Near net shaped 2-dimensional (2D) and 3-dimensional (3D) pre-forms (a mostly dry fiber lay-up that can later be infused with resin) can be made of UD tape or multi-directional tape (in which the plies are held together using a powder binder, inter-ply non-woven veil, and/or stitching).
• Pre-impregnated tape typically 1 !4 in to 24 in wide
• slit tape typically 1/8 in to 1 !4 in wide
• “towpreg” can also be laid down directly to shape on contoured tooling using AMP equipment (e.g., contoured tape laminating machine (CTLM), automated fiber placement (AFP) or robotic fiber placement (RFP) and subsequently cured in an oven or autoclave).
• CTLM contoured tape laminating machine
• AFP automated fiber placement
• RFP robotic fiber placement
• AFP offers considerable flexibility to produce near net-shape helicoidal preforms with all possible angles and an unlimited number of plies or patches to produce any desired helicoidal preform stacking sequence. These helicoidal materials represent a near net shape to the part.
• 2D or 3D preform structures can be made of dry fiber or UD Tape or multi-directional tape, forming several plies held together by means of a powder binder, inter-ply non-woven thermoplastic veil, needle or pneumatic air punching.
• a “towpreg”, or any kind of preimpregnated fiber, UD Tape, multi-directional tape or a slit tape of thermoplastic matrix & fiber can be deposited with a robotic fiber placement head to produce a helicoidal near net shape 2D or 3D preform that can already be impregnated as set forth in Figs. 7A-7B.
• Fig. 7A illustrates a helicoidal preform made of straight fiber placement on a 3D curved shape
• Fig. 7B illustrates a helicoidal preform made of curved fiber placement on a 2D shape.
• Continuous Tow Shearing (CTS) can be used to create in-plane curvilinear fiber orientations.
• NCF Non-Crimp Fabric
• Plies are usually stitched together but can be linked together by means of a powder binder or an interply nonwoven thermoplastic veil that is slightly melted.
• HMX Helicoidal Multiaxial
• a roll of 5 helicoid plies forming a Helicoidal Multiaxial (HMX) fabric [0°, 22.5°, 45°, 67.5°, 90°] can be produced.
• This roll can then be folded around its 0° axis dividing its width by 2 or simply combined with another same roll flipped over to form a 10-plies HMX: [-90°,- 67.5°,-45 o ,-22.5 o ,0 o ,0 o ,22.5°, 45°, 67.5°, 90°].
• a first helicoidal MX fabric (e.g., [56°, 79°, -79°, -56°]) can be taken off a large continuous roll and rotated 90° (e.g., [-34°,- 11°,11°,34°]) and placed on top of one another to create a 8-plies HMX fabric (e.g., 22° HMX with 8 plies [56°, 79°, -79°, -56°, -34°,-ll o ,l l o ,34°] ).
• two HMX stacks can be joined using stitching or powder binder or heat laminated thermoplastic nonwoven veil or any other suitable known technics such as air punch or needle punch.
• Hybrid construction Composite components have been made that incorporate nonpolymer and/or sandwich materials that can improve properties like bearing, stiffness and impact resistance. Examples of hybrid designs are provided below:
• Metals typically have limited elastic capability to dissipate energy and therefore fail catastrophically when loaded beyond their ultimate capability. Alternatively, metals can deform plastically to dissipate impact energy.
• Metal foils, meshes and fibers e.g., aluminum, titanium and steel
• SMA Shape Memory Alloys
• Typical fiber metal laminate (FML) forms in use in industry include: ARALL (aramid/aluminum), GLARE (fiberglass/aluminum), CARALL (carbon/aluminum), and TiGr (titanium/graphite).
• Additional metal/composite hybrid drawbacks include: (a) metals may have noncompatible coefficients of thermal expansion (CTE’s) when incorporated into polymer-based composites, (b) metal foils, meshes and fibers are difficult to place to complex contours, and (c) metals are denser than the composite material they are displacing.
• CTE coefficients of thermal expansion
• Sandwich structures Placing a material including, for example a polymer layer on a honeycomb core or foam material between composite laminate face sheets, as shown in Figs. 10A and 10B, creates a synergistic structural configuration in which the face sheets provide bending stiffness and the sandwich material provide shear rigidity and buckling resistance. Compared to monolithic laminate composites, sandwich panels can exhibit improved strength- to-weight ratios, sound deadening, fatigue capability, thermal insulation, and impact/damage resistance. Sandwich panel impact performance can be superior to laminates since some of the energy associated with a strike may dissipate as elastic deformation instead of matrix and/or fiber damage and/or the core may cushion inertial loads while the face sheet performs the energy absorption.
• Laminate face sheet configuration, core type/structural properties and boundary conditions control the impact behavior.
• the face sheets are relatively thin and the core is bonded to the face sheets with an adhesive.
• Structural and failure mechanisms that make sandwich inappropriate for some applications include the following: a) because of limited bond area and strength the face sheets may prematurely separate from the core during impact, b) since the face sheets are thin relative to an equivalent laminate design fiber breakage, fiber matrix de-bonding and laminate delamination can initiate at lower impact levels, c) the core can crush or experience shear deformation and d) replacing laminate plies with sandwich material can degrade in-plane structural properties like compression, tension, strength and stiffness
• Thin ply Composite laminates made from TPUD stacks have been shown to exhibit better mechanical properties and improved resistance to micro-cracking, delamination, and impact when compared to same thickness parts made using thicker plies.
• aerospace UD carbon/epoxy (C/E) pre-pregs are grade 190 (.0073 in/ply) or grade 145 (.0056 in/ply).
• TPUD is typically grade 75 (.003 in/ply) or thinner. The grade specifies the nominal areal weight of carbon fiber in UD pre-preg measured in g/m 2 .
• TPUD laminates allow for reduced minimum gauge and/or lighter weight equivalent performance structures.
• Fiber orientation controls load carrying capability. Therefore, it is best to run the bulk of the fibers in the direction of primary loading. Balance/symmetry rules along with rules for minimum orientation to protect from unexpected loads (e.g., no less than 10% of the fibers in any one direction) limit stacking freedom and often dictate a lay-up thicker than that needed expressively to take a given load case. These constraints are particularly challenging when tapering (dropping plies) in part areas of reduced loading.
• TPUD plies as a whole or in combination with normal thickness plies open lighter/thinner stacking options.
• TPUD can be harder and more costly to prepreg slit and re-roll and can suffer from more defects and be harder and/or more costly to lay down to a part shape using automated fiber placement equipment than traditional thicknesses pre-preg tape and therefore has seen limited usage in aerospace applications to date.
• TPUD tape takes more time to lay down to part shape than traditional thickness pre-preg tape due to the higher number of plies being placed.
• composite structures can be subjected to low and/or high velocity impacts from planned strikes, collisions, hail, rain, birds, tool drop, ballistics, random debris, shock waves, lightning strike or aero fluttering.
• a fiber reinforced elastic composite ply stacking approach in which the individual layers are rotated along the longitudinal or x-direction axis at a predefined angle relative to the adjacent layers so as to create a z-direction helicoidal fiber-oriented stack is depicted in Fig. 11.
• the left-hand image uses a single line to represent each ply layer (lamina), this view highlights the generated z direction helicoidal spiral.
• the right-hand image uses fiber bundles (tows typically consisting of 3000 to 50,000 fibers or more) to more realistically show the construction layers of a helicoidal lay-up.
• the subsequent blow ups show how the helicoidal laminate stack is formed of individual laminae layers that are formed of evenly dispersed spread fiber tow and resin.
• Helicoidal clocking can be chosen to create a specific spiraling pitch or circular polarization z orientation fibers that are in close enough proximity as to exhibit significant intralaminar-like direct load sharing between laminate fibers.
• These left and right-handed chirality (a non-superimposable structure distinguishable from its mirror image) spirals are novel when compared to industry standard 0°, ⁇ 45°, 90° composite laminates (note: in some cases 22.5°, 30°, and 60° angles are used but in these cases large clocking angles and symmetry /balance rules are still typical).
• spiral formed from the assembly of these pitched fibers can be tuned to a specific wavelength to dampen propagating shock waves initiated by ballistics, strike forces or foreign material impacts; can be filled with a matrix that contains microspheres or toughening particles to further prevent or arrest propagation of catastrophic fractures and can be made to exploit the difference in elastic moduli between the fibers and resin to further arrest fractures generated from blunt or sharp impacts.
• Certain disclosed enhancements include helicoidal materials containing: (a) nanomaterials, (b) variable pitch and partial spirals, (c) TPUD plies, (d) hybrid materials, (e) curved fiber within a ply, (f) automated fiber or tape or patch placement for 2D or 3D preforms, (g) non-crimped fabrics, (h) 3D woven fabrics, (i) 3D printed materials, and (j) filament wound parts , (1) TPW layups, (m) QUDW layups.
• Dry and/or pre-preg helicoidal lay-ups can be placed ply-by-ply by hand, direct placed on contoured tools with automated fiber placement machines, and/or pre-knitted in stacks using weaving/braiding/UD plies and woven fabric stitching equipment (e.g., noncrimp fabric machines).
• weaving/braiding/UD plies and woven fabric stitching equipment e.g., noncrimp fabric machines.
• Nanomaterials are property enhancing particles having dimensions in the 1 and 1000 nanometers (10 9 meter) range. Examples include carbon nanofibers (CNFs), carbon nanotubes (CNTs), single-wall nanotubes (SWNTs), multi-wall nanotubes (MWNTs), graphite platelets/graphene, organic spherical particles; copolymers, inorganic clays; silica, silicon carbide, alumina, metal oxides, and other known or yet to be evolved nano materials. Incorporation of nanomaterials into a resin in combination with fiber reinforcements has been shown to improve mechanical properties and impact resistance over conventional composite laminates of identical thickness. In some implementations, nanofibers (fibers having a diameter less than lOOnm) can be incorporated into the material.
• Figs. 14A-C show different types of impact damage (i.e. , deformation, intralaminar resin cracking, interlaminar resin cracking, fiber breakage and delamination) arising from different impact levels (i.e., low, medium, and high). With nanomaterials, impact improvement can be attributed to whiskering (i.e., nanoscale bridging between fibers that improves transverse and intralaminar shear properties).
• Figs. 15A-C show how nanoscale bridging (also known as stitching) is particularly effective between fibers of the same or similar orientation (i.e., same orientation intralaminar fibers or close orientation interlaminar fibers like the 5- degree helicoidal example shown in Fig. 13).
• nanomaterials can reduce or even eliminate resin cracks arising from low and medium level impacts. Since helicoidal lay-ups’ plies are clocked at shallow angles (e.g. 5 to 30 degrees), the direct contact length between individual interlaminar fibers is up to 10 times greater than with standard 0°, ⁇ 45°, 90° layups. This longer contact length makes nanocomposite additives more effective on helicoidal lay-ups than industry standard lay-ups that are separated by angles of 45 or 90 degrees.
• Helicoidal lay-ups with nano additives can exhibit not only reduced/eliminated intralaminar vertical/horizontal resin cracking but also reduced/eliminated horizontal interlaminar resin cracking and even delamination (total ply separation) arrest, as shown in the Figure 14B under medium impact. Nanomaterials can be added uniformly into the resin during pre-pregging, attached directly to the fibers or added as an interlaminar layer between ply stacks. [0035] Variable pitch and partial helicoidal structures: The pitch of a helicoidal lay-up depends on the per ply laminae thickness and the angle the plies are clocked/stacked at.
• the resultant spiral can be tuned to a specific wavelength or strength in anticipation of expected impact type/level and/or required strength.
• conventional layups (those using 0°, ⁇ 45°, 90° plies) require ply stacks to be balanced and symmetric.
• Certain prior art acknowledges that a helicoidal lay-up can be left hand, right hand or both direction spiraled. As originally envisioned, a helicoidal stack contains consistent angular offset throughout the entire lay-up.
• An example of a balanced and symmetric 18 degree offset helicoidal lay-up is (0°, 18°, 36°, 54°, 72°, 90°, -12°, -54°, -36°, -18°, 0°, -18°, -36°, -54°, - 72°, 90°, 72°, 54°, 36°, 18°, 0°).
• shallow clocking angles e.g. 30 degrees or less
• helicoidal lay-ups have less propensity to warp than industry standard 0°, ⁇ 45°, 90° lay-ups, even when not balanced and/or symmetric. This ability to make non-standard helicoidal layups allows for unique thinner laminate options that can be further tuned for specific applications.
• the current disclosure describes the additional helicoidal clocking options:
• Lay-ups with variable clocking angles in a single laminate such as 5, 10, 15 and 30 degrees.
• One example would be (0°, 5°, 15°, 30, 45°, 75°, -75°, -45°, 30 -15°, -5°, 0°).
• This type of lay-up is good for tuning over variable wavelengths, arresting/dissipating impact forces at a zone/depth in the lay-up and/or balancing between impact capability and overall laminate strength.
• This type of lay-up is good for dissipating impact loads within a certain thickness of the laminate while still allowing the freedom to tailor the orientation of other plies for strength in the load bearing direction.
• Non- symmetric and/or non-balanced lay-ups that are only left or right hand spiraled such as: (0°, 30°, 60°, 90°, -60°, -30°, 0°) and (0°, -30°, -60°, 90°, 60°, 30°, 0°). These lay-ups allow one to take advantage of helicoidal clocking, hence impact capability, without having to make a thick balanced/symmetric lay-up. Because tighter helicoidal clocking angles are used (not the traditional 0°, ⁇ 45°, 90°), such lay-ups have less propensity to warp. Further, the tendency to warp can often be overcome by part shape or local stiffening.
• lay-ups that are only partially spiraled and do not clock through a full 360 degree, such as: (0°, 5°, 10°, 15°, 90°, 90°, 15°, 10°, 5°, 0°) or (-35°, -25°, -15°, -5°, 5°, 15°, 25”, 35°).
• This clocking can be directional as to anticipate the nature and direction of impacts in service.
• TPUD helicoidal materials Industry typical UD carbon/epoxy (C/E) pre-preg grades include; 190 (.0073 in/ply) and 145 (.0056 in/ply). Thin ply pre-preg is typically grade 60 (.0023 in/ply) or thinner. Fig. 16 depicts how helicoidal ply thickness and clocking creates stair step spirals of various height and width. For example, a grade 145 UD helicoidal lay-up would have ⁇ 15 to 20 carbon fibers stacked on top of each other per ply for a vertical step of .0056 in.
• This 1 : 1 tightly clocked spiral with short interlaminar resin shear zone and substantial fiber to fiber direct contact is at the heart of helicoidal lay-ups’ impact resistant, crack arresting and interlaminar load sharing between capabilities.
• a grade 190 (.0073 in/ply) helicoidal lay-up with the same 5° clocking would have a roughly 2:1 stairstep.
• a typical grade 145 industry standard lay-up with 45° clocking would have a .056 in vertical resin step and therein a relatively long 1: 10 spiral.
• This long resin shear zone when compared to a helicoidal lay-up, limits interlaminar direct fiber load sharing and, in some instances, can account for reduced impact resistance.
• 90° clocking creates an interlaminar step of infinity (i.e., an undisturbed interlaminar resin zone).
• TPUD lay-ups have been shown to have improved strength and impact capability when compared to similar thickness traditional layups.
• a TPUD grade 60 (.0023 in/ply) helicoidal lay-up with 5° clocking would create an exemplary !4:1 stairstep.
• Such a pre-preg clocking arrangement has been shown to have up to a 50% impact improvement versus traditional (thickness and clocking) lay-ups.
• TPUD pre-preg TPUD pre-preg
• Microcrack arrestment will not only help maintain load carrying capability, but it will also reduce permeation of liquids and/or gases in containment vessels.
• TPUD variants are exceptional embodiments of the art:
• TPUD helicoidal stacks exhibit improved strength, impact and interlaminar microcrack arresting versus standard ply thickness traditional clocking lay-ups. These capabilities can be attributed to tighter aspect ratio spiraling and therein improved interlaminar load sharing.
• TPUD helicoidal stacks of continuously clocked spirals have strength as good or better than highly oriented traditional stacks (extra plies in the primary load carrying direction) while having improved impact characteristics. This is attributable to the fact that although the helicoidal lay-up may have fewer total fibers in the primary load direction, the thinner plies and slightly clocked off- angle fibers promote efficient interlaminar load sharing. Additionally, since identical angle fibers are not being stacked directly on top of each other in the helicoidal stack, there is less of a propensity for vertical resin microcracks to propagate between laminae during high loading and/or impact events and/or in cold weather environments. Microcrack arrestment will not only help maintain load carrying capability, but it will also reduce permeation of liquids and/or gases in containment vessels.
• TPUD helicoidal stacks of less total thickness may have similar or better impact strength than thicker traditional laminates. Therein, it is possible to make thinner and lighter laminates when using TPUD helicoidal stacks than when using industry non-helicoidal standard balanced, symmetric, and minimum direction orientation laminates. Thinner minimum gauge TPUD helicoidal stacks can possess desired properties while adhering to tradition lay-up symmetry, balance and minimum orientation rules. For example, an aircraft skin may require 8-plies of grade 190 UD tape or .058 in total thickness for hail strike when using standard 0°, ⁇ 45°, 90° layups rules, (0°, +45°, -45°, 90°, 90°, -45°, +45°, 0°).
• TPUD helicoidal lay-up (one using plies of .0023 in or less) might meet impact requirements and lay-up rules using a 16-ply .037 in laminate.
• Helicoidal stacks can combine TPUD and thick plies to create uniquely tuned and strength/impact laminates that are superior to traditional lay-ups.
• One drawback of TPUD is that it may require more time to lay-up a laminate when compared to a thick ply material part because more layers are needed. This drawback can partially be obviated by using a combination of thin and thick plies.
• thin helicoidal plies can be used for a portion of the lay-up to tune the lay-up and increase overall impact capability, while thick plies can be used to reduce lay-up time and create overall strength.
• helicoidal plies could be used near the outer surface of the laminate to improve impact strength and thick plies on the remainder or middle of the lay-up as the primary load carrying mechanism.
• a thick inner layer that uses unidirectional fibers, and this can be wrapped, or encapsulated, within a layer of helicoidal material.
• helicoidal material can be used on an inner layer of a pressure vessel to prevent cracks from propagating to an outer layer of the pressure vessel.
• a helicoidal material can be used for an intermediate or outer layer of a pressure vessel in addition to or instead of an inner layer of the pressure vessel.
• FIGs. 18A-C show schematic views of a ply arrangement for a fiber-reinforced composite structure 10 according to embodiments of the invention.
• Fig. 18B represents a cross section of the structure shown in perspective in Figs. 18A and 18C.
• the composite structure 10 has a first plurality of plies 11 of reinforcing fi bers defining a first region of the fiber reinforced composite structure, the plies comprising parallel fibers, and wherein the plies are arranged to provide load-canying strength for the reinforced composite structure.
• the first plurality 11 includes five plies.
• the two plies at the bottom are arranged at +807-80°, and the three plies above those are both arranged at 0°.
• the 0° plies are arranged along the axis of an axisymmetric part, such as a tubular structure, and provide strength in the direction of primary loading.
• the +807- 80° plies serve to reinforce the 0° plies and resist buckling of the axisymmetric part, such as might be advantageous in long, thin tubular structures.
• a second plurality’ of plies of reinforcing fibers 12 define a second region of the fiber reinforced composite structure and are arranged in a helicoidal relationship, and wherein an included angle between the orientation directions of at least two adjacent plies is more than 0° and less than about 30° to provide impact resistance for the reinforced composite structure.
• the plies starting from the top and working down
• the plies are arranged at 70°, 65°, 60°, 55°, 50°, 45°, 40°, 30°, 20°, and 10°.
• this helicoidal relationship provides impact resistance to the underlying structure.
• a third plurality of plies of reinforcing fibers may be positioned opposite the second plurality of plies of reinforcing fibers so as to provide impact resistance to both sides of the first plurality positioned in the middle of the second and third plies.
• TPUD plies for the second plurality of helicoidal plies and thick plies for the other plies, which provides advantages in terms of impact resistance, primary load carrying ability and reduced lay-up time, the thickness of the plies could be the same for each of the plies.
• TPUD helicoidal stacks can be made with variable clocking to create uniquely tuned laminates that still possess strength and impact properties that are superior to traditional lay-ups.
• the resultant laminate could therein possess a predetermined pitch and tuning that uniquely meets the demands of the products environment (as an example thermal, impact, and strength requirements) while minimizing part weight.
• TPUD and thick ply helicoidal stacks can be made with variable clocking to create uniquely tuned and strength/impact capable laminates that are superior to traditional lay-ups.
• thin and thick plies can be used to minimize lay-up cost and optimize strength/spiral tuning capabilities while variable clocking pitch can be used to maximize properties to a further degree or of a different nature.
• the thin and thick ply selection can be driven primarily from a lay-up cost standpoint while the variable clocking can be chosen to arrest vertical intralaminar resin microcracking.
• Other combinations of cost to strength, cost to impact resistance, and cost to weight tuning to improve cost-performance can be envisioned.
• One of the primary benefits of composite components is that they can be tailored by adding and dropping plies, therein increasing strength and impact resistance in areas of higher loading while maintaining minimal thickness and weight in other areas.
• Often parts are padded up around openings in the structure such as fastener locations and conduit pass-throughs and in bond zones to locally stiffen a component and/or improve bearing and/or structural strength like aerospace structural assembly with rivets, or a bicycle rim around spoke attachment points.
• parts are thickened in areas of expected high impact, like the leading edge of a wing or wind turbine blade, golf club, striking area of bats and clubs, protective helmets, etc.
• parts can be made to flex in one area and be stiff in other areas such as is the case with fishing poles, golf clubs, pole vault poles, sailing masts, skis & snowboards, running shoes etc.
• the pad-up regions of a component can consist of any of the helicoidal variants discussed in this disclosure. This pad- up can be incorporated with a base traditional lay-up or a base helicoidal lay-up of the same or different construction. As detailed in the eight previously listed exemplary cases, TPUD helicoidal laminates allow for reduced minimum gauge and/or lighter weight better or equivalent performing structures.
• Hybrid material helicoidal structures Helicoidal laminates including nanomaterials, variable pitch and partial spirals, and TPUD can be combined with hybrid materials (e.g., woven composites, non-polymers, metals, foams, sandwich materials, and/or other materials known or to be evolved in the industry) to improve properties like overall weight, fabrication cost, bearing, stiffness and impact resistance. These combinations can be done globally (e.g., nanomaterial combined throughout a matrix resin) or judiciously (e.g., a layer of titanium foil replacing four plies of traditional thickness pre-preg in a thin-thick helicoidal spiral) so as to dial in specific strength and impact characteristics while minimizing cost, weight and/or thickness. Specific exemplary examples of hybrid helicoidal structures are listed below:
• a helicoidal structure with woven fabric composites plies distributed in the stack or on the inner and outer surfaces can be created with unique clocking arrangements chosen to improve impact capability.
• Woven plies can be useful on the inner and outer surface to minimize fiber breakout when drilling or trimming and can improve erosion and impact capability.
• fabric can be used to create unique clocking/spiraling and tuning combinations that help absorb and dissipate impact forces and minimize the effects of impact fatigue.
• Fabric plies can also contain metal foils, fibers or meshes to help dissipate lightning strikes, transmit current, shield electrical components or change thermal conductivity.
• a helicoidal structure with metal foil on the inner and outer surfaces can be created to improve erosion and impact capability. Therein, the metal foil can obviate bearing failure, reduce or delay erosion, and/or yield under impact while allowing the helicoidal structure to remain intact for further impact resistance and load carrying.
• a layer of dampening foam or sandwich material in the center of a helicoidal stack can be done to increase shear rigidity, cushion inertial loads, dissipate strike energy, and/or improve buckling resistance.
• Such construction can improve component strength-to-weight ratios, sound deadening, fatigue capability, thermal insulation, and impact/ damage resistance.
• helicoidal TPUD skins in a sandwich construction replacing traditional skin structures made of Biaxial (e.g., [+x°/-x°]), Tri-axial (e.g., [0°,+x°,-x°]) or Quadriaxial (i. e. , [0°, ⁇ 45°, 90°]), or Woven Fabric allows for the improvement of through- thickness impact strength of the skin and to delay skin buckling under inplane compression. This results from smaller interply angles and a larger number of plies which leads to weight savings. In such a structure the helicoidal stacking delivers higher through-thickness impact strength and complements and counterbalances weaknesses typical of thin ply laminates in out-of-plane strength. Thus, helicoidal stacking of thin plies permits improvement of in-plane properties of thin plies for increased weight reduction.
• Biaxial e.g., [+x°/-x°]
• Tri-axial e.g., [0°,+x°,-x
• Nanomaterials can be incorporated into a matrix resin to improve the bond between helicoidal plies themselves and hybrid materials (e.g., metals and sandwich) and therein improve interlaminar strength and properties relying on such (e.g., strength shear, bending tensile, compression and impact).
• the thickness or weight of a skin can relate to the ultimate intended application for the sandwich structure.
• a skin has a total fabric fiber areal weight of lower than about 1,600 gsm. This weight of fabric may be used for surfboards, for example.
• the skin has a total fabric fiber areal weight of lower than about 5,000 gsm. This weight of fabric may be used for wind turbine blades made from E-glass fibers, for example.
• the skin has a thickness of less than about 4mm.
• the weight of the skin may be lower than about 3,000 gsm according to embodiments.
• the skin of the composite sandwich structure may have a partially directional (or quasi-isotropic) strength profile and with improved impact resistance.
• the helicoidal arrangement of the skin has superior in-plane compression resistance.
• the off-axis plies i.e. plies which fiber direction is not aligned along the loading direction
• the off-axis plies usually are the first one to fail with the formation of matrix cracks.
• matrix cracks often begin in a direction parallel to the off-axis plies such that they are aligned within and/or adjacent to the tows of an off-axis ply. From there, the matrix cracks propagate into interface damage between plies, which causes delamination, and can lead to early catastrophic failure. This is particularly evident in conventional skins with off-axis plies oriented along medium to large orientations, e.g. ⁇ 30°, ⁇ 45° and ⁇ 60° and 90° orientations.
• a helicoidal fiber arrangement provides a better load redistribution along the off-axis plies, making it more difficult for a crack to form and propagate. This is due to one or both of at least two reasons.
• a helicoidal fiber arrangement typically has fewer off-axis plies and/or off-axis plies positioned at smaller angles relative to the reference direction (0°) as compared to conventional skins and thus providing fewer sites for matrix cracks to initiate.
• the propagation of interlaminar cracks at the interface between two plies is determined at least in part by the interlaminar shear stress, which in turn is driven at least in part by the difference in directional elasticity from one ply to the next.
• a larger change in elasticity from one ply to the next along a common reference direction is more likely to lead to interlaminar matrix cracks.
• the smooth transition in fiber orientation between adj acent plies in helicoid structures reduces the difference in elasticity from one ply to the next (relative to conventional skins), which in turn reduces the interlaminar stresses at the interface between plies and delays crack propagation and delamination under an increasing compressive load.
• delaminations can lead to local decrease in the stiffness of the skin which can result in early buckling of the skins.
• the formation of delaminations would be delayed, leading to better compression strength.
• the in-plane compression resistance of a helicoidal skin is especially advantageous in sandwich structures because the bending or flexural resistance (as determined by the industry- known three-point bending test) of composite structures is often limited by the skin of the sandwich that is subjected to the compressive load (as opposed to an opposite skin that is subjected to the tensile load).
• the sandwich structure can have a three- layer construction with two helicoidal skins and a core material therebetween.
• embodiments of the invention also include three-layer constructions where only one of the skins is a helicoidal skin, and an opposing skin can comprise, for example, a conventional composite material.
• the core may comprise more than one layer of material and/or be formed of more than one type of core material. Additional layers of composite material may also be included to provide stiffening or other structural properties.
• Curved fibers within a ply can be created using traditional or robotic fiber placement equipment.
• relatively narrow strips of slit tape or tow e.g. in
• a wider band e.g., 4 in
• the placement head can alter heat, placement pressure and angular shear laydown forces in a manner so that the band can be steered in an arc (e.g., 200 mm radius), s-shape or any desired contour instead of the traditional straight line orientation used when placing most composites, see Fig. 17.
• This curvature can add more degrees of freedom to a helicoidal stack and can be used with any of the alternative designs discussed within this disclosure.
• In-plane curving within a 2D or 3D shape combined with helicoidal ply stacking can further enhance wavelength tuning and impact capabilities.
• Thin-ply woven (TPW) fabrics are an emerging class of high -performance fiber reinforced materials to provide high strength and abrasion resistance.
• TPW fabrics are typically found in two forms: 1) spread tow fabrics, where a tow is spread into a thin and flat unidirectional tape (with fiber areal weight similar to the ones of TPUD) and then the various tapes are woven to form a fabric; and 2) fabrics made using light tows, as shown in Fig. 19.
• Light tows are defined herein as tows having lk-12k filaments per tow in the case of carbon filaments and having a weight of less than about 300 tex for glass.
• Light tow TPW fibers can also comprise natural fibers ( ⁇ 320 tex), aramid fibers ( ⁇ 300 tex), UHMWPE fibers ( ⁇ 300 tex), polypropylene fibers (( ⁇ 200 tex), and other typical fibers commonly used in composites and mixtures thereof.
• TPW fabrics are laid-up helicoidally and offer superior impact performance compared to conventional thick tows.
• Helicoidal lay-ups of woven fabrics as used herein refers to helicoidal lay-ups wherein the included angle between two corresponding tow directions of abutting fabric layers are offset by a helicoidal angle.
• the warp tows of two overlaid woven fabrics can be offset by 5° [so as to define a 0757... arrangement], and thus the weft tows would be offset by 90° accordingly [in 907957... directions],
• the superior impact performance of helicoidal TPW layups as disclosed herein lies in the ability of sub-critical matrix splits (as caused by an impact) to more progressively grow and nest within the laminate in a spiral cracking pattern.
• the failure mechanism typically starts with a split in the matrix, which has a lower tensile strength (in isolation) than the fiber material.
• This split may start at a portion of the matrix between the tows, or it may start through the tow (and parallel to its fiber orientation direction) as shown in Figs. 20A-C.
• Fig. 20A shows two layers of conventional woven fabrics with intersecting warp tows and weft tows, Fig.
• Fig. 20B shows two layers of spread tow TPW fabrics
• Fig. 20C shows two layers of light-tow TPW fabrics.
• the split will need to cross the fibers of the next tow in the direction of the split.
• this next tow is generally orthogonal to the split tow, and thus the split will need to break the fibers of the next tow (in their tensile direction) as shown for layers 1 and 2 for Figs. 20A-C.
• the translaminar fracture toughness in fiber reinforced composites increases with the ply thickness. However, contrary to what might be expected, the translaminar fracture toughness does not increase linearly with increased ply thickness. As an example, doubling the ply thickness or tow count requires more than double the energy required for the crack to propagate. This is related to the activation of additional energy dissipation mechanisms such as splitting, delamination, kink bands (compression) and fiber pull-outs (tension) that contribute to the energy dissipation process.
• TPW fabrics with lower tow count and/or spread tow layers greatly reduces the amount of energy required to break the weft thin-tow/spread tow (on a relative basis) hence allowing the failure mechanisms of helicoidal structures to activate without instability.
• a composite structure having TPW fabric layers stacked in a helicoidal arrangement can exhibit a spiral cracking pattern and thus superior impact resistance as compared to conventional thick ply woven fabric composites that might fail in an unstable fashion.
• Example uses for TPW fabric composites include sporting goods, automotive/motorsports components (including wings, splitters, diffusers, body panels) and marine components (including hulls, masts, decks).
• Other example uses include consumer goods, such as suitcases and luggage.
• Suitcases and luggage made from polypropylene fibers according to embodiments of the invention provide impact protection and toughness at a reasonable cost.
• Quasi-Uni-Directional Woven (QUDW) fabrics can be provided in standard, thick, and thin woven fabrics and arranged helicoidally to provide enhanced impact performance.
• QUDW fabrics are highly unbalanced fabrics where more than >80% of the fibers are aligned along the warp direction and the complementary percentage ( ⁇ 20%) is aligned along the weft direction with the function of providing stability and drapability to the fabric as shown in Figs. 21A-C.
• the fibers of the weft can be different from the fibers of the warp to maximize the difference in elastic properties with the warp fibers (i.e. load carrying fibers).
• the fibers along the warp direction could be made with glass fiber to provide the bulk of the stiffness and strength to the ply using a relatively low-price fiber type.
• the fibers of the weft tows ( ⁇ 20%) could be made of carbon fiber, which is more expensive but better performing than glass, to provide a stiffening effect to the direction orthogonal to the warp.
• the unbalancing of the fabrics and relative spacing between the dispersed weft yams is advantageous to achieve enhanced impact performance when the QUDW fabrics are arranged helicoidally to achieve the failure mechanisms of helicoid layups according to embodiments of the invention.
• a matrix split that forms along the warp can propagate in the neighboring ply-fabric without being halted by a weft yam crossing over the warp yam.
• fibers are not required to break to allow for the helicoidal crack to form and grow to take advantage of the helicoidal layup failure mechanisms.
• embodiments of the invention include larger included angles for QUDW fabrics.
• the regions where the weft yams of two adjacent plies overlap cause a higher resistance to the propagation of helicoidal cracks because the energy required for a crack to propagate helicoidally will require it to break the fibers of the weft yams. This might lead to unstable catastrophic failure.
• Fig. 22A shows two QUDW plies with 95% warp fibers and 5% weft fibers
• Fig. 22B shows two QUDW plies with 75% warp fibers and 25% weft fibers.
• QUDW fabrics can be made of carbon fibers and other fiber types typically used in composites.
• the warp and/or weft yams can be formed from glass fibers.
• Example uses for QUDW fabric composites include sporting goods, automotive/motorsports components (including body panels, chassis components, battery casings, skid plates), wind turbine blades, pipes and marine components (including hulls, masts, decks).
• the present disclosure details a range of novel helicoidal design and manufacturing enhancements that are beyond the prior art.
• This disclosure teaches modifications to spiraling pitch and construction material/altematives in specific including: (a) nanomaterials, (b) variable pitch and partial spirals, (c) TPUD, (d) hybrid materials, (e) curved fibers within a ply, (f) automated fiber or tape placement for 2D or 3D preforms, (g) noncrimped fabrics, (h) 3D woven fabrics, (i) 3D printed materials, and (j) filament wound parts, (1) TPW, and (m) QUDW.
• Example 1 Helicoidal structures containing nanomaterials including but not limited to CNFs, CNTs, SWNTs, MWNTs, graphite platelets/graphene, organic spherical particles, copolymers, inorganic clays, silica, silicon carbide, alumina, metal oxides, and other known or yet to be evolved nano materials. Incorporation of nanomaterials into a resin in combination with fiber reinforcements has been shown to improve mechanical properties and impact resistance over conventional composite laminates of identical thickness. If desired, it is possible to incorporate nanofibers (fibers having a diameter less than lOOnm) into the material.
• nanofibers fibers having a diameter less than lOOnm
• Nanomaterial whiskering between fibers can improve transverse and intralaminar shear properties and reduce or even eliminate resin cracks arising from low and medium level impacts.
• Helicoidal lay-ups with shallow clocking angles that increase direct contact length between interlaminar fibers can improve whiskering effects. This lengthening of the contact length, resultant from tight helicoidal clocking, makes nanocomposite additives more effective when incorporated into helicoidal lay-ups than when used in industry standard lay-ups.
• Helicoidal lay-ups with nano-additives can exhibit not only reduced/eliminated intralaminar vertical/horizontal resin cracking but also reduced/eliminated horizontal interlaminar resin cracks and forestalled onset of delamination.
• Example 2 TPUD helicoidal structures create tightly clocked spirals with short interlaminar resin shear zones and substantial fiber to fiber direct contact. Such lay-ups are impact resistant, crack arresting (both from impact and low temperatures) and have improved interlaminar load sharing capabilities. TPUD helicoidal laminates allow for reduced minimum gauge and/or lighter weight better or equivalent performing structures. Balance/symmetry rules along with rules for minimum orientation to protect for unexpected loading (e.g., no less than 10% of the fibers in any one direction) that limit stacking freedom and often dictate lay-ups thicker than needed expressively to take a given load case can be used more sparingly with TPUD helicoidal structures or in some cases ignored. Specific variants of this example include the following:
• Helicoidal stacks that combine TPUD and thick plies to create uniquely tuned and strength/impact laminates that are superior to traditional lay-ups.
• thin helicoidal plies can be used for a portion of the lay-up to tune the lay-up and increase overall impact capability, while thick plies can be used to reduce lay-up time and create overall strength.
• TPUD helicoidal stacks with variable clocking to create uniquely tuned laminates that still possess strength and impact properties that are superior to traditional lay-ups.
• Pad-up regions of a component can include any of the helicoidal variants discussed in this disclosure. This pad-up can be incorporated with a base traditional lay-up or a base helicoidal lay-up of the same or different construction.
• Hybrid material helicoidal structures can be created using any of the previously mentioned nanomaterials, variable pitch and partial spirals, and TPUD plies in combination with hybrid materials (e.g., non-polymer, metals, foams and/or sandwich materials) to improve strength, bearing, stiffness and impact resistance. These combinations can be done globally or just in selected regions to dial in specific strength and impact characteristics while minimizing cost, weight and/or thickness. Specific variants of this example include the following:
• Fabric plies can also contain metal foils, fibers or meshes to help dissipate lightning strikes, transmit current, shield electrical components or change thermal conductivity.
• Helicoidal materials can be made using thin ply uni-directional (TPUD) materials assembled in a sandwich construction replacing the traditional skin structure made of Non-Crimp Fabrics or Woven Fabrics.
• TPUD thin ply uni-directional
• This structure permits a corresponding improvement of impact strength and also can help delay skin buckling under in-plane compression.
• the helicoidal TPUD stacking can be expected to deliver relatively higher through-thickness impact strength and complement and counterbalance the weakness of thin ply laminates in out of plane strength.
• helicoidal stacking of TPUD permits enhancement of in-plane properties of thin plies that can in turn permit weight reduction of parts.
• Helicoidal variants that use nanomaterials in the resin to improve the bond between helicoidal plies themselves and hybrid materials (e.g., metals and sandwich) and therein improve interlaminar strength and properties relying on such (e.g., strength shear, bending tensile, compression and impact).
• Example 4 Automated material placement equipment for deposition of continuous fiber, tape or fiber patches can be used to create any of the previously mentioned helicoidal designs with the added enhancement of curving the fibers within a given ply. This curvature can add more degrees of freedom to a 2D or 3D shape helicoidal stack and can be used to further enhance wavelength tuning and impact capabilities.
• Example 5 Helicoidal Multiaxial (HMX) non-crimp fabric [0°, 22.5°, 45°, 67.5°, 90°] can be produced. This roll can then be folded around its 0° axis dividing its width by 2 or simply combined with another same roll flipped over to form a 10-plies HMX: [-90°,-67.5°,- 45°, -22.5°, 0°,0°, 22.5°, 45°, 67.5°, 90°].
• HMX Helicoidal Multiaxial
• a first helicoidal MX fabric (e.g., [56°, 79°, -79°, -56°]) can be taken off a large continuous roll and rotated 90° (e.g., [-34°,- 11°,11°,34°]) and placed on top of one another to create a 8-plies HMX fabric (e.g., 22° HMX with 8 plies [56°, 79°, -79°, -56°, -34°,-ll o ,l l o ,34°] ).
• two HMX stacks can be joined using stitching or powder binder or heat laminated thermoplastic nonwoven veil or any other suitable known technics such as air punch or needle punch.
• Example 6 Filament Winding can be used to create structures based on a helicoidal architecture for various kinds of axisymmetric parts such as pipes, tapered tubes, as well as tanks and pressure vessels (typically in form of a sphere or a cylinder which may have domes on one or both ends).
• these filament winded parts need to be highly resistant to external impact and are crash and drop tested (such as a hydrogen pressure vessel in the form of a fuel tank in a vehicle) so as to withstand major crashes and avoid exploding.
• Such structures can be made using full or partial helicoidal laminates to enhance impact strength and to also have more diffused crack propagation to avoid gas leakage and extend operational life cycle.
• Filament winding techniques can be used to interlace helicoidally formed unidirectional fiber band or tapes, for example, by winding from one end to the other end over a mandrel.
• Such an interlaced helicoidal pattern (as illustrated, for example, in Fig. 5H) can complete the mandrel coverage with a bi-angle +X°/-X° double layer. This angle can be measured from tire mandrel rotational axis which accounts for the 0° angular reference.
• this filament winding technique it is therefore possible to create successive interlaced helicoidal double layers with a small shallow clocking angle therebetween (e.g. 5° to 10°) around the 0° or the 90° orientations. Around the 45° direction, fibers will cross nearly orthogonally.
• a structure having a helicoidal architecture can be manufactured with filament winding by winding a layer of fibers all having same angle, or variable angles within the layer/ply. This can be accomplished by programming a robotic filament winding machine accordingly to wind the desired pattern or by adjusting the setup of the roving dispenser. This technique permits winding several full surface plies of fibers with a small variation ofclocking angle between plies to obtain the benefit of a helicoidal architecture.
• winding successive circumferential plies at relative angles close to 90° will provide a product, such as a pressure vessel, with much higher impact strength and more diffuse crack propagation.
• a product such as a pressure vessel
• Such a helicoidal architecture can also be used as an internal layer to enhance the safety factor in regard to gas leakage through cracks within a partially damaged laminate structure.
• Pull-winding processes can combine pultrusion of a profile with a 0° main direction of liber reinforcement with wound fibers or tapes to bring further resistance to a transverse load.
• These wound plies can also be adjacent with a small variation of their angle to from a structure having a helicoidal architecture and deliver higher transverse impact resistance properties.
• Example 7 Braids and Skewed Fabrics.
• Braids produced using 2D or 3D techniques offer an interesting property of diameter variation associated with fiber angle variation. As fibers can slip within a tubular braid, this allows to expand or reduce the diameter of such braid. This property can be advantageous to create a structure having a helicoidal architecture with several layers effectively sleeved over one another so as to progressively expand the diameter of the structure and to slightly vary the fiber angle between and/or along layers to create a very small clocking angle variation between two adjacent braided layers.
• Such braided fiber reinforcing structures can also be provided in the form of a flat braided tape obtained from a tubular braid cut along a longitudinal direction and then laid open flat.
• the fiber angular orientation also varies with the width of the tape.
• Such braided tape can also be used to stack different layers of the same tape with slightly different fiber angle to create a structure having a helicoidal architecture.
• This property' can also be found in woven fabrics which are skewed to modify the initial 90° angle between warp and weft which can be timed to create a series of warp/weft angles with small angular variations from one fabric layer to the next one (such as a 5° clocking angle to align layers at 90°, 85°, 80° ,75° degrees, etc.) thus creating a structure having a helicoidal architecture.
• Example 8 Additive Manufacturing. Many of the aforementioned techniques use existing sets of fabrics, pre-pregs, and the like. In this example, an alternative method for forming helicoidal architectures is provided. There are multiple routes to additive manufacturing, including stereolithography (SLA) that uses lasers to cure layer by layer photopolymer resins, fused deposition modeling (FDM) that uses 3D printers to deposit thermoplastic materials, multijet modeling (MJM) that can build materials via a printer head depositing materials in 3 dimensions, and selective laser sintering (SLS), which uses a high powered laser to fuse small polymer, metallic, or ceramic/glass particles together. In all of these aforementioned techniques, a helicoidal structure can be constructed.
• SLA stereolithography
• FDM fused deposition modeling
• MJM multijet modeling
• SLS selective laser sintering
• multiple printer jets can be used to print, simultaneously, two or more materials that can both have the helicoidal structure, but be offset by a specific angle (e.g., a double helicoid), or have one material act as the in-plane helicoid and another material be printed out of plane, acting as a z-pinned structure.
• materials do not have to be printed in a solid fibrous form.
• a “core-shell” print head can be used to print core-shell materials, where the shell is the desired final material and the core is used as a sacrificial template.
• a hydrophobic polymer such as polypropylene (PP) can be co-printed with polyvinyl alcohol (PVA) as the core. After printing, the structure can be placed in an aqueous bath that will subsequently remove the PVA, yielding hollow PP fibers/tubes.
• the materials do not have to be printed as polymers, but as ceramic-based precursors (e.g., SiC, B4C, etc.).
• a ceramic precursor e.g., poly carbosilane, a precursor to SiC
• the ceramic precursor Upon annealing at a low temperature (e.g., 200°C), the ceramic precursor will solidify (not yet transform to SiC).
• the PVA can be safely removed without collapsing the tubes and then the resulting structures can be annealed to completely transform the ceramic precursor to a given material (e.g., SiC).
• the resulting fibers can be micro or nano-tubes, which can act as transport channels for fluids (air, water, self-healing resin, thermal cooling material, etc.).
• the stiffness or hardness (or any other material property that depends on material composition, particle size, etc.) of the material being deposited can be graded by continuously changing the material in the print reservoir.
• the rotational angle of the helicoid can further be tuned to form a graded helicoidal composite material, which may also provide additional mechanical benefit.
• existing templated structures can be placed on the print stage as a scaffold or sacrificial structure that will yield an architecture that goes beyond just a helicoidal architecture.
• a 2D or even 3D array of pins, tubes or other structures can be placed on the build plate of a SLA printer.
• the helicoidal architecture can be printed around this scaffold and subsequently the scaffold can be removed, yielding a multistructure with helicoidal architecture that maintains impact resistance, but offers additional benefits (for example, mechanical benefits such as z-pinning and thermal: cooling).
• the 3D printing technology can be used to print curved structures with ease.
• a simple CAD model can be constructed to enable an FDM printer (for example) to place fibers in a helicoidal array, but in a curved macrostructural part.
• Example 9 TPW and QUDW fabrics helicoidal structures brings together the benefits of the superior impact resistance of helicoidal architectures with the class of woven fabrics for improved drapability, reduced layup time, improved abrasion and visuals. Such lay-ups are impact resistant, crack arresting (both from impact and low temperatures) and have improved interlaminar load sharing capabilities. TPW and QUDW helicoidal laminates allow for structural weight reduction, by improving the impact performances of conventional woven laminates while reducing manufacturing costs of helicoidal structures. The presence of weft and warp fibers eliminates the problem of using balanced/unbalanced layups delivering helicoid solutions with a much wider design space. Specific variants of this example include the following:
• TPW and/or QUDW Helicoidal stacks that combine TPUD, thick plies and thick woven plies to create uniquely tuned and strength/impact laminates that are superior to traditional lay-ups.
• TPW helicoidal plies are used for the top portion of the lay-up to locally improve abrasion resistance, visuals and impact resistance, while TPUD or thick UD plies can be used to provide tailored stiffness and in-plane strength.
• TPW and/or QUDW helicoidal stacks with variable clocking to create uniquely tuned laminates that still possess strength and impact properties that are superior to traditional lay-ups.
• Example 10 Conventional lightweight sandwich structures comprise a core, usually PVC, EPS, Honeycomb, Aramid fiber Honeycomb, shear thickening foam cores (D3O®), metamaterial cores (MetaCORETM, MetaCORE-LDTM, MetaTHERMTM) and similar to provide stiffness, acoustic impedance, reduced weight and other structural and mechanical properties.
• Lightweight fiber-reinforced composite skins with a total fiber areal weight of 5000gsm and lower and/or with a skin thickness of 4mm and lower are used to provide strength and stiffness to the sandwich structure in lightweight sandwich applications.
• TPUD TPUD
• QUDW TPW
• NCF TPW
• UD UD
• a sandwich application includes 200gsm skins for application to a 5mm thick PVC core.
• a skin is formed using 10 layers of 20gsm carbon filament TPUD arranged with the parallel fibers of each ply defining orientation directions as [-15/-25/-35/-45/-60/60/45/35/25/15] to create a helicoidal relationship.
• Fig 23B shows a conventional TPUD biaxial with a [+45Z-45] 5 relationship.
• Fig. 24 shows the results of a three-point bending flexural test pursuant to ASTM D7249.
• the helicoid TPUD layup When compared to an equivalent TPUD biaxial [+45/-45]s, the helicoid TPUD layup showed increased flexural strength of 88% and 54% when tested along the longitudinal (0°) and transverse (90°) direction, respectively (note that with conventional biaxial, the 0° and 90° properties are expected to be equivalent). As compared to an equivalent standard thick biaxial [+45°/-45°] layer of equal weight, the helicoid TPUD layup according to this example showed increased flexural strength of 118% and 77%, tested along the longitudinal and transverse direction, respectively.
• the resultant innovative sandwich with directional helicoid skins thus offers superior compressive strength of the skins in both the longitudinal and orthogonal loading direction.
• the helicoidal arrangement achieves higher stiffness and strength also along the orthogonal direction which, in the helicoidal is characterized by a lower percentage of fiber components aligned to the load than the reference [+457-45].
• Helicoidal skins wherein all layers are TPW plies, or QUDW plies or TPUD, or NCF, or UD plies.
• TPW or QUDW or TPUD or NCF or UD Helicoidal skins that combine TPUD, NCF, thick plies and thick woven plies to create uniquely tuned and strength/impact skins that are superior to traditional skins.
• one layer of TPW can be used as top skins to improve visual appeal and anti-abrasion resistance while TPUD helicoidal plies can be used for the rest of the skin to provide tailored impact resistance, stiffness, and in-plane strength.
• Sandwich applications with only the top (impact-facing) helicoidal skin This is to offer an impact resistant mechanism where the overall stiffness is offered by geometrical features of the structures, such as in applications with a double curvature or complex shapes.
• Such architecture confers higher stress redistribution during impact, further improving impact performances.
• top skin is helicoidal and the bottom skin is non- helicoidal and where the top and bottom skins can have similar or different weights. For instance, a thicker top helicoidal skin to provide compression strength and impact resistance, while a bottom non-helicoid skin to provide flexural tensile strength and stiffness.
• a helicoidal composite ply clocking/ stacking design and methodology in which composite plies are stacked in a tight spiral to specific pitches in order to create a z-direction fiber arrangement that will dampen and absorb shockwave propagation, dissipate strain energy, minimize the effects of impact fatigue, and minimize and/or arrest damage associated with impacts.
• the helicoidal system in aspect 1 that is laid up by hand, direct placed with automated machines, and/or pre-knitted in stacks using weavmg/brai ding/ stitching equipment (e.g., non-crimp fabric machines).
• pre-knitted stack e.g. 4, 6, 10, or more specifically clocked helicoidal plies chosen for strength and impact resistance
• the stack can be dry and later liquid molded or made from pre-preg.
• This stack can be the entire part or a specific area of the component chosen for helicoidal enhancement using any of the variants disclosed in this disclosure.
• the helicoidal system in aspect I where matrix resin alteration (e.g., lowering monomer functionality, increasing the backbone molecular weight, or incorporation of flexible subgroups) and/or additives (e.g,, microspheres, discrete rubber, thermoplastic particle or veils) are used to toughen the laminate and further arrest propagation of catastrophic fractures.
• matrix resin alteration e.g., lowering monomer functionality, increasing the backbone molecular weight, or incorporation of flexible subgroups
• additives e.g, microspheres, discrete rubber, thermoplastic particle or veils
• the helicoidal system in aspect 1, where the pad-up regions of a component can include any of the helicoidal variants discussed in this disclosure with a base traditional lay-up or a base helicoidal lay-up of the same or different construction.
• a helicoidal system in aspects 1 through 7, with nanomaterials e.g., CNFs, CNTs, SWNTs, MWNTs, graphite platelets/graphene, organic spherical particles, copolymers, inorganic clays, silica, silicon carbide, alumina, metal oxides, and other known or yet to be evolved nano materials
• nanomaterials e.g., CNFs, CNTs, SWNTs, MWNTs, graphite platelets/graphene, organic spherical particles, copolymers, inorganic clays, silica, silicon carbide, alumina, metal oxides, and other known or yet to be evolved nano materials
• the resultant helicoidal/nanomaterial hybrid has nanoscale whiskers/connections that bridge and allow for sharing between the fibers, improve overall laminate mechanical properties, improve impact resistance and have crack arresting characteristics.
• a helicoidal system in aspect 11 with variable clocking angles (i.e., 5°, 10°, 15°) in a single laminate that are tuned over variable wavelengths, arrest/dissipate impact forces at a particular zone/depth and can be optimized for a preferred combination of impact capability and overall laminate strength.
• Such lay-ups can take advantage of helicoidal clocking benefits without having to increase thickness to adhere to balance and symmetry rules of thumb.
• Components made with shallow' helicoidal clocking angles have less propensity to warp than traditional 0°, ⁇ 45°, 90° lay-ups. Further, any tendency to warp can often be overcome by part shape or local stiffening effects.
• the specific construction of such woven fabrics, characterized by either low translaminar fracture toughness of the weft yams (TPW) and large spacing between weft yams (QUDW) can be tailored to allow for the highly dissipative failure mechanisms of helicoidal structure to activate and lead to enhanced impact performances.
• the use of woven fabrics allows to improve drapability of helicoid stack to complex shapes and reduce layup costs.
• the resultant tightly clocked helicoidal spirals have relatively short interlaminar resin shear zones hence substantial fiber to fiber direct contact/load sharing (i.e., tight aspect ratios) which make them impact resistant and crack arresting capable.
• TPUD lay-ups have been shown to have improved strength when compared to similar thickness traditional lay-ups. 19.
• the helicoidal system in aspect 16 that not only has superior resin crack arrest capability from impact events but also exhibits the capability to minimize intra and inter laminar cracking due to extreme environments (e.g., -200 to 415°F temperatures) such as would be experienced during space and cryogenic tank applications.
• the hehcoidal system in aspect 16 with continuously clocked spirals that exhibit strength as good or better than highly oriented traditional stacks (extra plies in the primary' load carrying direction) while having improved impact characteristics.
• the combination of thinner plies and slightly clocked off-angle fibers combine to make efficient interlaminar load sharing that results in superior in-plane strength capabilities.
• the helicoidal system in aspect 16 while having less total thickness than a comparable traditional laminate stack, may have similar or better strength and impact capability. Therein, it is possible to make thinner and lighter TPUD helicoidal laminates than is possible when adhering to industry' standard balance, symmetry’, and minimum direction orientation rules.
• the hehcoidal system in aspect 16 of a thinner or minimum gauge (a thickness that will take critical load case such as hail or bird strike) while still possessing desired properties and adhering to traditional lay-up symmetry, balance and minimum orientation rules.
• the helicoidal system in aspect 16 that can combine TPUD and thick plies to create uniquely’ tuned, strength and impact capability' components.
• thin helicoidal plies can be used for a portion of the lay-up to tune the lay-up and increase impact capability, while thick plies can be used to reduce lay-up time and create overall in-plane strength.
• a helicoidal TPUD non-symmetric/non-balanced stack can have a minimal gauge and low weight.
• the helicoidal system in aspect 16 with combined TPUD and thick ply helicoidal stacks and variable clocking to create uniquely tuned and siren gth/impact laminates that are superior to traditional lay-ups.
• the thin and thick plies can be used to minimize lay-up cost and optimize strength/spiral tuning variables to a certain degree while the variable clocking pitch can be used to optimize properties.
• the helicoidal system in aspect 16, where the pad-up regions of a component can include any of the TPUD variants described in 17 through 24 with a base traditional layup or a base helicoidal lay-up of the same or different construction.
• the helicoidal systems in aspects 1 through 25 combined with hybrid materials (e.g., non-polymer, metals, foams and/or sandwich materials) to improve strength, bearing, stiffness and/or impact resistance.
• hybrid materials e.g., non-polymer, metals, foams and/or sandwich materials
• Such combinations can be done globally (e.g., nanomaterial combined throughout a matrix resin) or selectively (e.g., a layer of titanium foil) as dictated to meet specific strength, erosion, and impact characteristics while minimizing cost, weight and/or thickness.
• hybrid material e.g., metals and sandwich
• the helicoidal system in aspect 26 with fabric composite plies selectively placed in the stack or on the inner and outer surfaces to create unique clocking arrangements specifically chosen to absorb and dissipate impact forces. Also, when used on the outer plies, to minimize fiber breakout during drilling or trimming. Fabric plies can also contain metal foils, fibers or meshes to help dissipate lightning strikes, transmit current, shield electrical components or change thermal conductivity. 31.
• the helicoidal systems in aspect 17 and 18 with a dampening foam or sandwich material in the center of a helicoidal stack to increase shear rigi di tv. cushion inertial loads, dissipate strike energy, and/or improve buckling resistance.
• a method of making a helicoidal structure from a non-crimp fabric using a multiaxial fabric machine is a method of making a helicoidal structure from a non-crimp fabric using a multiaxial fabric machine.
• HMX Multiaxial Helicoid Non-Crimp Fabric
• HMX eight or ten plies roll of material
• H-NCF12 o [48°, 60°, 72°, 84°, -84°, -72°, -60°, -48°] or H-NCF22.5°:[90,-67.5,- 45,-22.5,0,0,22.5, 45, 67.5,90] ).

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)
• Moulding By Coating Moulds (AREA)
• Reinforced Plastic Materials (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=82059687

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (3)

• 2021
  • 2021-06-28 WO PCT/US2021/039399 patent/WO2022132228A1/en active Application Filing
  • 2021-06-28 KR KR1020237024079A patent/KR20230131473A/ko active Search and Examination
  • 2021-06-28 JP JP2023537108A patent/JP2023554637A/ja active Pending
  • 2021-06-28 EP EP21907356.6A patent/EP4263207A1/de active Pending

Also Published As

Similar Documents

Legal Events