BR102018004513B1 - METHOD FOR GENERATING A LAYER FORMATION OF A LAMINATE, NON-TRAINER COMPUTER READABLE MEDIUM, AND, SYSTEM FOR GENERATING A LAYER FORMATION OF A LAMINATE - Google Patents

Abstract

Systems and methods are provided for the design of flat composites that are formed into 3D shapes. One embodiment is a method that includes loading data defining a three-dimensional (3D) shape for a composite part, identifying constraints based on the dimensions of the 3D shape, simulating flattening the 3D shape to a planar shape, and acquiring a mandrel having the planar shape. The method further includes placing features on the mandrel that allow a laminate to be formed in layers on the mandrel, compensating for constraints during forming the laminate into 3D shape, and generating a Numerical Control (NC) program that directs a placement machine. of Automated Fiber (AFP) forming the laminate in layers. The NC program includes instructions for layering tows of constituent material onto the mandrel having the characteristics to form layers of the laminate.

Description

TECHNICAL FIELD

[001] The invention relates to the field of composite materials and, in particular, to the formation of layers carried out by an Automated Fiber Laying (AFP) machine (also known as an Automated Tape Layering Machine, ATL) .

FUNDAMENTALS

[002] Composite parts, such as those made from carbon fiber reinforced polymer (CFRP), combine high levels of mechanical strength with low weight. This combination is desirable in the field of aircraft design and manufacturing. Manufacturing a composite part involves layering constituent material into layers to form a laminate. The constituent material may comprise a ribbon including parallel carbon fibers pre-impregnated with curable resin. This pre-impregnated tape is also called “pre-preg” tape. AFP machines can be used to predictably and reliably perform the formation of pre-preg tape layers in an automated manner based on a Numerical Control (NC) program. The resulting laminate is then cured to harden into a composite part.

[003] Many desired shapes for composite parts are complex and three-dimensional (3D). Although AFP machines are capable of layering complex 3D shapes, the operating speed of an AFP machine, especially when layering sharp corners, is substantially reduced. Therefore, the amount of time (and therefore expense) involved in forming layers of complex 3D laminates is substantially greater than for flat laminates (e.g., laminates that have largely planar shapes, and that have a lower weight than than one-tenth of its width and/or length. Additionally, it can be particularly difficult to maintain a laminate in a 3D shape before the laminate has been cured.

[004] Composite part designers can use AFP machines to layer flat laminates to be cured into flat composite parts, but the flat laminates fail to capture any complex surface geometry desired for a composite part (e.g., ensuring an aerodynamic shape ). Additionally, it is not feasible to form flat laminates into complex 3D shapes. This is because the carbon fiber within a flat laminate is highly resistant to stretching. Therefore, wrinkles may form in the resulting shape as the flat laminate is formed (e.g., molded).

[005] Therefore, designers of composite parts continue to search for techniques to form a part with a complex contour from flat material, without generating wrinkles.

SUMMARY

[006] Embodiments described here generate designs for flat laminates to include features that enable flat laminates to be formed (e.g., stamped/pressed/molded) into complex 3D shapes without creasing, wrinkling, warping or cracking. These “2.5D” laminates include layering characteristics (e.g., excess material) at predefined locations. These features enable their corresponding locations to be formed according to a desired 3D shape without losing structural integrity. In other embodiments, an AFP machine layering such laminates can detect discrepancies in tow placement during physical layering, and alter an NC program directing layering so as to ensure that new layers of tape are placed on top. the gaps.

[007] One embodiment is a method that includes loading data defining a three-dimensional (3D) shape for a composite part, identifying limitations based on dimensions of the 3D shape, simulating flattening the 3D shape to a planar shape, and acquiring a mandrel having a flat shape. The method further includes mandrel placement features that allow layering of laminates on the mandrel to compensate for limitations during forming the laminate into 3D shape, and generating a Numerical Control (NC) program that directs a placement machine. automated fiber (AFP) that forms the laminate in layers. The NC program includes instructions for forming layers of constituent material onto the mandrel having the characteristics to form layers of the laminate.

[008] Another embodiment is a non-transitory computer-readable medium incorporating programmed instructions that, when executed by a processor, are operable to execute the method. The method includes placing features on a planar mandrel that allow laminate layering on the mandrel to compensate for constraints corresponding to a three-dimensional (3D) shape during forming the laminate into the 3D shape, and generating a Numerical Control (NC) program. ) that directs an Automated Fiber Placement (AFP) machine to form the laminate in layers. The NC program includes instructions for forming layers of strands of constituent material onto the planar mandrel, including features placed on the mandrel to form layers of the laminate. The method also includes forming layers of the laminate according to the NC program, and forming the laminate into 3D shape.

[009] Another embodiment is a system that includes a memory that stores data defining a three-dimensional (3D) shape for a composite part. The system further includes a controller that loads data, identifies constraints based on the dimensions of the 3D shape, flattens the 3D shape to a planar shape, and places features on the planar shape that allow a layered laminate to compensate for constraints during sheet formation. laminated to 3D shape. The controller also generates a Numerical Control (NC) program that directs an Automated Fiber Laying (AFP) machine to layer the laminate, the NC program including instructions for layering tow and constituent material for forming layers of the laminate. laminate.

[0010] An additional embodiment is a method that includes forming a composite part by: layering a two-dimensional (2D) laminate on a mandrel that has characteristics that cause folds to be formed in layers such that expected shear between the folds is already incorporated into the two-dimensional (2D) laminate, and form the two-dimensional (2D) laminate in a preform with a complex contour, including the effect of the expected shear between the folds.

[0011] Other exemplary modalities (e.g., methods and computer-readable media relative to the preceding modalities) will be described below. The explained features, functions and advantages may be obtained independently in various embodiments, or may be combined in other embodiments, the details of which may be viewed with reference to the following description and drawings.

DESCRIPTION OF THE DRAWINGS

[0012] Some embodiments of the present invention will now be described, by way of example only, and with reference to the attached drawings. The same reference number represents the same element or the same type of element in all drawings.

[0013] Figure 1 is a diagram of an AFP machine in an exemplary embodiment.

[0014] Figure 2 is a block diagram illustrating a layering design system interacting with an AFP machine to layer a flat laminate in an exemplary embodiment.

[0015] Figures 3A-3B are flowcharts illustrating a method for generating a layer formation of a laminate that will be formed into a 3D shape in an exemplary embodiment.

[0016] Figure 4 is a flowchart illustrating a method for revisions in the course of execution for an NC program driving an AFP machine in an exemplary embodiment.

[0017] Figure 5 is a diagram illustrating a composite part in an exemplary embodiment.

[0018] Figure 6 is a diagram illustrating a first formation of layers for the composite part of Figure 5 in an exemplary embodiment.

[0019] Figure 7 is a diagram illustrating additional layer formation for the composite part of Figure 5 in an exemplary embodiment.

[0020] Figures 8-9 are diagrams illustrating a tow directed in a layer formation for a composite part in an exemplary embodiment.

[0021] Figure 10 is a diagram of a 3D composite part formed from a laminate in an exemplary embodiment.

[0022] Figures 11-12 are views of the laminate used to form the composite part of figure 10 in an exemplary embodiment.

[0023] Figure 13 is a flowchart of aircraft production and maintenance methodology in an exemplary modality.

[0024] Figure 14 is a block diagram of an aircraft in an exemplary embodiment.

DESCRIPTION

[0025] The following figures and description illustrate specific exemplary modalities of the invention. It should therefore be appreciated that one skilled in the art will be able to imagine various arrangements which, although not explicitly described or shown here, embody the principles of the invention and are included within the scope of the invention. Additionally, any examples described herein are intended to aid in understanding the principles of the invention, and should be considered as being without limitation to these specifically cited examples and conditions. As a result, the invention is not limited to the specific embodiments or examples described below, but by the claims and their equivalents.

[0026] Figure 1 is a diagram illustrating the AFP machine 100 that is mounted to a support 170 in an exemplary embodiment. The AFP machine 100 comprises any system or device capable of layering tow 152 of constituent material to form a laminate 150 for curing into a composite part. The AFP machine 100 includes an effector/head 180, which dispenses tows 152 of curable constituent material (e.g., pre-preg carbon tape tape for a CFRP part) during layer formation. The tow 152 is formed in layers to form laminate 150, which comprises one or more layers of material that will be cured into a single monolithic composite piece.

[0027] As the AFP machine 100 operates to layer tow 152 onto laminate 150, the AFP machine 100 may move directly toward/away from the laminate 150 along the X axis 166, vertically upward/ downward along the Y axis 164, and/or sideways along the Z axis 162. As used herein, when the AFP machine forms multiple layers of tow 152 concurrently during a single “sweep” of the head 180, those tow 152 are collectively referred to as a single “course”. A set of non-overlapping strokes that are applied consecutively can be referred to as a layer. Once the layers are added to the laminate 150, the strength of the composite part is beneficially enhanced.

[0028] In order to ensure that the tow 152 is formed into layers quickly and efficiently, the operations of the AFP machine 100 are controlled by an NC program. In one embodiment, the NC program provides instructions on a stroke-by-stroke basis to align/reposition the AFP machine 100, move the head 180, and layer tow 152 onto the laminate 150. Thereby, by executing the program instructions of NC, the AFP 100 machine manufactures a laminate to be cured into a composite part.

[0029] Although the AFP machine 100 is illustrated as layering a complex curved shape in a 3D space, this process is not always optimally efficient. Moving an AFP 100 machine across a curved surface may involve constant repositioning and realignment of an AFP machine head, which slows down the AFP 100 machine. For these reasons, the AFP 100 machine has been designed to cooperate with an AFP 100 machine design system. layering that enables laminates to be formed into layers as flat shapes (increasing layering speed) that include layering features that facilitate shaping (e.g., stamping) into desired 3D shapes. As used herein, a form, mandrel or laminate is considered “flat” if its height is less than ten percent (e.g., less than two percent) of the amount of its width and/or length. A shape is considered a 3D shape if it is not a flat shape.

[0030] Figure 2 is a block diagram illustrating a layering design system 3210 interacting with an AFP machine 220 layering a flat laminate 240 in an exemplary embodiment. In this embodiment, layering design system 210 includes controller 212, which generates NC program 218 defining operations to layer a flat laminate 240. Controller 212 includes layering features in the NC program that ensure this laminate 240 be capable of being formed (e.g., molded/stamped) from its current shape to a desired 3D shape. The controller 212 may be implemented, for example, as a normal circuit, as a hardware processor executing programmed instructions, or some combination thereof. The layering design system 210 further includes a memory 214 that stores data defining a desired 3D shape 216 for a composite part, as well as at least one NC program 218 generated by the controller 212. The memory 214 may comprise any medium computer-readable format for storing data.

[0031] The AFP machine 220 layers tow 244 of constituent material (e.g., carbon fiber reinforced polymer (CFRP)) onto the mandrel 260 based on the instructions of the NC program 218. In this embodiment, the AFP machine 220 It comprises kinematic chain 222 of actuators and rigid bodies, which operate to position the end effector 224 as the end effector 224 layers tow 244 to form layers 242 of laminate 240. Camera 230 is also illustrated, which may comprise a camera 3D, stereoscopic, or with depth sensor. Camera 230 can be mounted to the AFP machine 220 or controlled independently. Based on the images 219 acquired by the camera 230 during layering, the controller 212 can adjust instructions contained in the NC program 218. At the end of layering, the laminate 240 is removed from the mandrel 260 and formed, for example, by stamping of the laminate 240 between the upper mold 252 and lower mold 254.

[0032] Illustrative details of the operation of layer forming design system 210 will be explained with respect to figures 3A-3B. Assume, for this embodiment, that a designer has provided input to the layering design system 210 indicating a desired 3D shape of a composite part. Figure 3A is a flow chart illustrating a method 300 for generating a layer formation of a laminate that will be formed into a 3D shape in an exemplary embodiment. The steps of method 300 are described with reference to the layering design system 210 of Figure 2, but one skilled in the art will appreciate that method 300 can be carried out in other systems. The steps in the flowcharts described here are not all inclusive and may include other steps not shown. The steps described here can also be formed in an alternative order.

[0033] For method 300, controller 212 loads data defining a 3D shape for a composite part (step 302). This data can, for example, indicate dimensions and positions of various features of a 3D shape/structure, in a Computer Aided Design (CAD) file or 3D model file. The controller 212 further identifies constraints based on the dimensions of the 3D shape (step 304. The constraints comprise, for example, radii of various portions (e.g., corners) of the 3D shape, distances between locations on the 3D shape, etc. The controller 212 simulates the flattening of the 3D shape to a planar shape (e.g., for layering as a laminate, or for use as a flat mandrel) (step 306). This simulation of flattening, or “unrolling,” anticipates how the material within of the 3D shape would be spread outward, to a flat pattern comprising multiple planar layers, and may involve placing cuts in the material to enable the material to be spread.

[0034] During unrolling, segmented 2D shapes can be extracted from the 3D shape and used to generate cutter files. These cutter files indicate one or more flat 2D shapes for cutting from a roll of material. For example, cutter files may provide instructions for cutting “pre-preg” pieces of laminate that are capable of being joined together to form a 3D shape. However, a designer may consider multi-piece laminates to be undesirable compared to monolithic laminates.

[0035] With constraints identified and an unrolling of the 3D shape to a planar shape successfully accomplished, controller 212 considers layering features to be added to the planar shape, based on the constraints.

[0036] Layering characteristics are physical changes to the planar shape, which ensure wrinkles are not formed during formation from the planar shape to the 3D shape. That is, the layering characteristics ensure that wrinkles are not formed when a laminate is formed into a complex 3D contour. In one embodiment, features are placed on a mandrel 260 that allow a laminate formed in layers on the mandrel 260 to compensate for constraints during forming the laminate into a 3D shape. In other embodiments, the controller 212 may join individual pieces/pieces of the rolled laminate to enhance strength while ensuring that the resulting laminate is capable of being formed into a desired shape. That is, the controller 212 ensures that segmented 2D shapes found in the controller files are rejoined using CAD software to a large planar shape representing a laminate that will be formed into layers according to a desired series of operations by the AFP machine.

[0037] Thus, instead of designing a 2D shape and then trying to transform it into a complex 3D contour, controller 212 starts with a complex contoured 3D CAD structure, flattens it into digital space, and determines a layer formation for a 2D laminate. The laminate will be used to create a wrinkle-free 3D structure (a “2.5D” layering). This reverse engineering approach therefore uses transformations from 3D to 2D and back to 3D throughout the design process.

[0038] During the creation of a layer formation for the laminate, the planar shape is converted into a “2.5D” geometry. This process involves an understanding of the constraints of the 3D geometry to be manufactured. That is, features are added to the planar shape at expected locations of wrinkles or gaps in unidirectional tape/tow during forming in order to add or remove material from the resulting laminate. This initial 2.5D geometry undergoes a 3D forming simulation that considers the placement and orientation of fibers in the laminate. During the 3D forming simulation, the resulting laminate is analyzed for potential wrinkles and formation difficulties caused by layer slip/shear (e.g., locations of substantial stress and stress, locations where excess material exists after forming, etc. ). Controller 212 then adjusts the 2.5D geometry based on this information and iteratively repeats the process of engaging in 3D forming simulations and updating the 2.5D geometry. That is, controller 212 iteratively simulates the placement of features on the mandrel, generates a simulation of forming a layered laminate on the mandrel into 3D shape, and changes the features based on expected wrinkles or cracks indicated by the simulation.

[0039] An upgrade to 2.5D geometry may comprise adjusting a length of layered material at a certain location, adjusting fiber orientations for one or more layers of the laminate, adding surface features to a mandrel, etc. In one embodiment, the controller 212 adds the layering characteristics by predicting an amount of distance that the laminate will expand during forming, and adding the length of tow to the laminate corresponding to the amount. For example, these predictions may take into account expected fold shear (e.g., fold slip) along one or multiple dimensions in each of multiple areas of interest on the planar shape. Several iterations of this simulation, followed by thinning of the 2.5D geometry, facilitate identification of critical locations in the geometry in which to avoid wrinkles.

[0040] With knowledge of the desired characteristics stored in memory, the controller 212 proceeds to acquire a chuck having a planar shape (step 308). Controller 212 places features on the mandrel that allow a laminate formed in layers on the mandrel to compensate for constraints identified during forming the laminate into 3D shape (step 310). This may comprise, for example, physically machining or otherwise altering the chuck.

[0041] The controller 212 also generates NC program 218, (step 312), which directs the AFP machine 220 to form layers of the laminate on a flat mandrel. The NC program 218 includes instructions for layering tows of constituent material to form layers of the laminate on a planar mandrel, including features (e.g., compensation features on the mandrel or laminate, depending on the embodiment). This means that instead of the NC program causing the laminate to be formed in layers on a 3D mandrel that already exhibits a complex contour. The NC 218 program provides instructions for layering the laminate on a flat mandrel. The mandrel and/or layering includes features that do not significantly alter the overall plan shape of the mandrel. For example, the added features may be small enough in height (e.g., less than ten percent of the width or length) so that the mandrel and laminate remain flat. In this way, the 2.5D geometry can then be converted into a layer forming pattern for an AFP machine, or it can be used to modify a mandrel to include surface features that ensure that wrinkles are not created during forming.

[0042] Figure 3B illustrates another method 350 relating to creating 2.5D laminates. According to Figure 3B, the controller 212 directs the AFP machine 220 to layer a 2D laminate on a mandrel having features that cause the plies to be formed in layers such that the expected shear between the plies (e.g., example, during forming) is already incorporated into the 2D laminate (step 352). This can be carried out according to the NC program 218. Next, the 2D laminate is formed (e.g., stamped) into a complex contour preform (step 354). This operation performs the expected shear between the plies as the laminate acquires the desired 3D shape. Briefly, the planar mandrel has characteristics that provide material used for layer sliding/shearing. In this way, when the 2.5D layer formation is formed into the 3-D shape, the material necessary to achieve the desired layer slip becomes available.

[0043] During layer formation, it remains possible that certain tows 244 are not placed in their desired locations, due to translational inconsistencies in the AFP machine 220, unexpected material variations, etc. For this reason, Figure 4 provides a method 400 for updating and revising the NC program 218 during the process, to ensure that discrepancies in physical layering are handled quickly and effectively.

[0044] Method 400 includes controller 212 acquiring images (via camera 230) of tow 244 placed by AFP machine 220 during layer formation (step 402). The controller 212 further determines actual locations of tows 244 placed in the AFP machine 220 during layering based on the acquired images (step 404). The controller 212 proceeds to compare actual tow locations 244 with expected tow locations 244 indicated by the NC program 218 (step 406). Controller 212 detects discrepancies between actual locations and expected locations (408), and alters NC program 218 during layering based on these discrepancies (step 410). For example, controller 212 may identify a tow illustrated by an image, correlate the tow to a tow identified in NC program 218, determine the actual location of the tow in a coordinate space used by NC program 218, and determine whether there is a discrepancy. IF the discrepancy comprises a gap between tows, the controller 212 may alter the NC program 218 to cover the gap by adding instructions to place tows over the gap. If the discrepancy comprises a tow having an actual location that is offset from an expected location, the controller 212 may alter the NC program via instruction revision to place tows in other layers based on the offset.

[0045] Methods 300 and 400, when used in combination, enable a flat laminate to be shaped into a desired 3D shape without unduly deforming, breaking, or damaging carbon fibers within the laminate. Additionally, these methods enable a designer to ensure that a laminate is formed into layers in the intended manner, by engaging in closed-loop control of the operations of an AFP machine during layer formation.

EXAMPLES

[0046] In the following examples, additional processes, systems and methods are described in the context of laminates that include layering features that allow laminates to be formed into 3D parts without being damaged or deformed.

[0047] Figure 5 is a diagram illustrating a composite part 500 in an exemplary embodiment. The composite part 500 includes body 510, upper flange 520, and lower flange 530. Each flange includes an outer corner 542 as well as an inner corner 544, and these corners contour the upper surface 550 and the lower surface 560. As shown in figure 5, a distance (L0) from a flange edge to an external corner is greater than a distance (LI) from a flange edge to an internal corner. This means that a purely planar laminate having a planar shape 620 comprising a large 2D contour as shown in Figure 6 would encounter deformations in the regions 610 if stamped and then cured to form the composite part 500. To address these problems, as shown in Figure 7, The controller 212 of Figure 2 has added layering features to the laminate 720 in the form of layering features 710 (e.g., protrusions), which are placed on the mandrel 730, which results in a 2.5D geometry. These features alter the amount of material formed into layers in regions 610, which ensures that enough material is present to account for the inner and outer corners of the composite part 500. These layering features 710 can be integrated into the mandrel 730, while the most of the mandrel remains flat, removable modules can be applied to the 730 mandrel using rapid manufacturing techniques, etc. In this way, plies are formed in layers with expected shear between the plies (i.e., ply slip) already included in the shape of the laminate.

[0048] Figures 8-9 are diagrams illustrating a layering feature comprising directed tows in a layering formation for a composite part in an exemplary embodiment. A directed tow can be layered onto a completely flat mandrel 730 to form a planar shape, and can provide additional material to enable a 2.5D laminate 810 to conform to 3D curvature during forming. In this embodiment, the tows 812 are directed so that they move in plane along the surface of the mandrel 820 and thus all have the same height.

[0049] Figure 10 is a diagram of a 3D composite part 1000 formed from a laminate in an exemplary embodiment. Figures 1112 are views of the laminate 1100 used to form the composite part 1000 of Figure 10 in an exemplary embodiment. Specifically, Figure 11 is a top view, and Figure 12 is a sectional view corresponding to view arrows 12 of Figure 11. In this embodiment, the laminate 1100 includes an annular protuberance/ridge 1120, including peak 1125. The protuberance annular 1120 comprises material that ensures that the laminate 1100 can be formed to match the 3D shape of the composite part 1000. The laminate 1100 further includes central portion 1130, and excess regions (e.g., scrap 1110). During forming laminate 1100 for part 1000, the central portion 1130 is known to be stretched, but tearing is prevented by the excess material found in the annular protuberance 1120. By balancing the amount of material placed in these different regions, the part 1000 can be formed without the formation of wrinkles or cracks.

[0050] With reference more particularly to the drawings, embodiments of the invention may be described in the context of a method of manufacturing and maintaining an aircraft 1300, as shown in figure 13, and an aircraft 1302, as shown in figure 14. During pre-production, The exemplary method 1300 may include specifications and design 1304 of the aircraft 1302 and material acquisition 1306. During production, manufacturing of components and sub-assembly 1308 and system integration 1310 of the aircraft 1302 occur. Then, the aircraft 1302 may undergo certification and dispatch 1312 to be placed into service 1314. While in service by a customer, the aircraft 1302 is scheduled for routine maintenance and overhaul 1316 (which may also include modification, reconfiguration, renewal, etc. .). Apparatus and methods incorporated herein may be employed during any one or more suitable stages of method and production and service 1300 (e.g., specification and design 1304, material acquisition 1306, component manufacturing and sub-assembly 1308, system integration 1310, certification and dispatch 1312, service 1314, maintenance and overhaul 1316, systems 1320, interior 1322, propulsion 1324, electrical 1326, hydraulics 1328, environment 1330).

[0051] Each of the processes of method 1300 can be performed or executed by a system integrator, a third party, and/or an operator (e.g., a customer). For purposes of this description, a system integrator may include, without limitation, any number of aircraft major system subcontractor manufacturers; a third party may include, without limitation, any number of vendors, subcontractors and suppliers; and an operator may be an airline, leasing company, military entity, service organization, etc.

[0052] As shown in Figure 14, aircraft 1302 produced by exemplary method 1300 may include a fuselage 1318 with a plurality of systems 1320 and an interior 1322. Examples of high-level systems 1320 include one or more than one propulsion system 1324 , an electrical system 1326, a hydraulic system 1328, and an environmental system 1330. Any number of other systems may be included. Although an aerospace example is shown, the principles of the invention can be applied to other industry sectors, such as the automotive industry.

[0053] As already mentioned above, apparatus and methods incorporated herein may be employed during any one or more stages of production and service method 1300. For example, components or sub-assemblies corresponding to production stage 1308 may be manufactured or manufactured from in a similar manner to components or sub-assemblies produced while the 1302 aircraft is in service. Additionally, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized during production stages 1308 and 1310, for example, to substantially speed up assembly, or, reduce the cost of an aircraft 1302. Similarly, one or more apparatus embodiments, method embodiments, or combination thereof may be used while aircraft 1302 is in service, for example, and without limitation, for maintenance and overhaul 1316. For example, the techniques and systems described herein may be used for steps 1306, 1308, 1310, 1314 and/or 1316, and/or may be used for fuselage 1318 and/or interior 1322. These techniques and systems may further be utilized by systems 1320, including, for example, propulsion 1324 , electrical 1326, hydraulic 1328, and/or environmental 1330.

[0054] In one embodiment, the laminate 240 is cured into a composite part comprising a fuselage portion 1318, and is manufactured during the fabrication of components and sub-assembly 1308. The composite can then be assembled into an aircraft in system integration 1310 and then be used in service 1314 until wear renders the part unusable. Then, at maintenance and overhaul 1316, the composite can be discarded and replaced with a new manufactured part. The enhanced layering design techniques described herein can be utilized throughout component and subassembly manufacturing 1308 to manufacture additional composite parts.

[0055] Any of the various control elements (e.g., electrical or electronic components) shown in the figures or described herein may be implemented as hardware, a processor implementation software, a processor implementation firmware, or some combination thereof. For example, an element may be implemented as dedicated hardware. Dedicated hardware elements may be referred to as “processors”, “controllers”, or some similar terminology. When provided by a processor, functions may be provided by a single dedicated processor, a single shared processor, or a plurality of individual processors, some of which may be shared. Additionally, the explicit use of the term “processor or controller” should not be considered to refer exclusively to hardware capable of executing software, and may, implicitly, include, without limitation, digital signal processor (DSP) hardware, a network, application-specific integrated circuit (ASIC) or other circuit, field-programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), non-volatile storage, logic, or any other physical hardware component or module.

[0056] Additionally, a control element can be implemented according to instructions executable by a processor or computer to perform the functions of the element. Some examples of instructions are software, program code and firmware. Instructions are operational when executed by the processor to direct the processor to perform the element's functions. Instructions can be stored on storage devices that are readable by the processor. Some examples of storage devices are digital or solid-state memories, magnetic storage media such as magnetic disks and magnetic tapes, hard drives, or optically read digital data storage media.

[0057] The present invention is also referred to in the following clauses that should not be confused with the claims.

[0058] A1. A method comprising: loading data defining a three-dimensional (3D) shape for a composite part (302); identify constraints based on 3D shape dimensions (304); simulate flattening of the 3D shape to a planar shape (306); acquire a mandrel having a planar shape (308); placing features on the mandrel that allow the formation of layers of a laminate on the mandrel to compensate for constraints during forming the laminate into 3D shape (310); generate a Numerical Control (NC) program that directs an Automated Fiber Laying (AFP) machine to layer the laminate, the NC program including instructions to layer tows of constituent material onto the mandrel having the characteristics, to form laminate layers (312).

[0059] A2. The method of paragraph A1 is further provided, further comprising: layering the laminate on the planar mandrel in accordance with the NC program.

[0060] A3. The method of paragraph A2 is further provided, further comprising: forming the laminate after layering has been completed.

[0061] A4. The method of paragraph A3 is additionally provided, in which: forming the laminate comprises: placing the laminate between complementary forming tools; and drive the forming tools towards each other to form the laminate.

[0062] A5. The method of paragraph A2 is further provided, further comprising: acquiring images of tow placed by the AFP machine during layer formation (402); determining actual locations of tow placed by the AFP machine during layer formation based on the images (404); compare the actual tow locations with the expected tow locations indicated by the NC program (406); detect discrepancies between actual locations and expected locations (408); and changing the NC program during layering based on discrepancies (410).

[0063] A6. Further provided is the method of paragraph A5, wherein: a discrepancy comprises a tow having an actual location that is displaced from an expected location; and changing the NC program involves revising instructions for placing tow in other layers based on displacement.

[0064] A7. Further provided is the method of paragraph A5, wherein: a discrepancy comprises a tow having an actual location that is displaced from an expected location; and changing the NC program involves revising instructions for placing tow in other layers based on displacement.

[0065] A8. Further provided is the method of paragraph A5, wherein: determining actual tow locations comprises placing tows on images in an NC program coordinate space, based on a position and orientation of a camera.

[0063] A9. The method of paragraph A2 is further provided, further comprising: curing the laminate on the composite part.

[0064] A10. The method of paragraph A1 is additionally provided, further comprising: iteratively: simulating placement of features in the mandrel; generate a simulation forming a formation of laminate layers on the mandrel in 3D form; and enhance the characteristics based on the expected wrinkles or cracks indicated by the simulation.

[0066] According to another aspect of the present invention, it is provided:

[0067] B1. A non-transitory computer-readable medium incorporating programmed instructions that, when executed by a processor, are operable to perform a method comprising: placing features on a planar mandrel that permit a laminate formed in layers over the mandrel to compensate for constraints corresponding to a three-dimensional shape (3D) during formation of the amino acid in the 3D form (310); and generating a Numerical Control (NC) program that directs an Automated Fiber Laying (AFP) machine to layer the laminate, the NC program including instructions for layering tows of constituent material onto the planar mandrel, including the characteristics placed in the mandrel to form layers of the laminate (312); layering the laminate according to the NC program (352); and forming the laminate into 3D shape (354).

[0068] B2. The means of paragraph B1 is further provided in which the method further comprises: loading data defining the 3D shape; identify constraints based on the dimensions of the 3D shape; flatten the 3D shape to a planar shape; and manufacturing the mandrel according to the planar shape.

[0069] B3. Further provided is the means of paragraph B1, in which: adding the features comprises adding changes to a surface of the chuck.

[0070] B4. The means of paragraph B1 is further provided in which the method further comprises: placing the laminate between complementary forming tools; and trigger the forming tools towards each other during modeling

[0071] According to another aspect of the present invention, there is provided: C1. A system comprising: a memory (214) that stores data (216) defining a three-dimensional (3D) shape for a composite part; and a controller (212) that loads the data, identifies constraints based on the dimensions of the 3D shape, flattens the 3D shape to a planar shape (620), and places features (710) on the planar shape that allow for laminate layer formation. (240) compensate for constraints during forming the laminate into 3D shape, the controller generates a Numerical Control (CN) program (218) that directs an Automated Fiber Placement (AFP) machine (100) to layer the laminate, p NC program including instructions for forming layers of tow (244) of constituent material to form layers (242) of the laminate.

[0072] C2. The system of paragraph C1 is additionally provided, in which: the controller additionally directs the curing of the laminate in the composite part.

[0073] C3. The system of paragraph C1 is further provided, wherein: the features include changes to a surface of a flat mandrel upon which the laminate is formed in layers.

[0074] C4. Further provided is the system of paragraph C1, wherein: features include tows (244) that are directed within a layer (242) of the laminate to increase an amount of material in the laminate.

[0075] C5. Further provided is the system of paragraph C1, wherein: the controller adds the characteristics by predicting a distance amount (L0-LI) by which a portion of the planar shape will expand during forming, and adds tow length to the shape planar corresponding to the quantity.

[0076] C6. The system of paragraph C1 is further provided, further comprising: a camera (230) that acquires images (219) of tows (244) placed by the AFP machine during layer formation, wherein the controller enters a closed feedback loop comprising determining actual locations of tow placed by the AFP machine based on the images, compare actual tow locations with expected tow locations indicated by the NC program, detect discrepancies between actual locations and expected locations, and change the NC program during forming layers based on discrepancies.

[0077] C7. The system in paragraph C6 is further provided, whereby: a discrepancy comprises a gap between tows; and the controller changes the NC program to cover the gap by adding instructions to place tow over the gap.

[0078] C8. Additionally provided is the system of paragraph C6, wherein: the controller determines actual tow locations by placing tows illustrated in the images in an NC program coordinate space, based on a camera position and orientation.

[0079] According to another aspect of the present invention, there is provided: D1. A method comprising: forming a composite part by means of: layering a two-dimensional (2D) laminate on a mandrel having features that cause the plies to be formed in layers such that the expected shear between the plies is already included in 2D laminate (352); and forming the 2D laminate into a complex contour preform, including performing the expected shear between the (354) D2 plies. Further provided is the method of paragraph D1, wherein: the features comprise tows that are directed within a layer of the laminate to increase an amount of laminate material D3. The method of paragraph D1 is further provided, wherein: the characteristics comprise additional tow lengths D4. The method of paragraph D1 is further provided, wherein: forming the laminate comprises stamping the laminate between complementary forming tools. D5. Further provided is the method of paragraph D1, wherein: the 2D laminate is planar, and the features comprise vertical disturbances in the 2D laminate.

[0080] Although specific embodiments are described here, the scope of the invention is not limited to these specific embodiments. The scope of the invention is defined by the following claims and any of their equivalents.

Claims (14)

1. Method for generating a formation of layers of a laminate, characterized by the fact that it comprises: loading data defining a three-dimensional (3D) shape for a composite part (302); identify constraints based on the dimensions of the 3D shape (304); simulate flattening of the 3D shape to a planar shape (306); acquire a mandrel having a planar shape (308); placing features on the mandrel that allow the formation of layers of a laminate on the mandrel to compensate for constraints during forming the laminate into 3D shape (310); and generating a Numerical Control (NC) program that directs an Automated Fiber Laying (AFP) machine to layer the laminate, the NC program including instructions for layering tows of constituent material onto the mandrel having the characteristics, to form layers of the laminate (312). 2. Method according to claim 1, further characterized by the fact that it comprises: layering the laminate on the planar mandrel in accordance with the NC program. 3. Method according to claim 2, further characterized by the fact that it comprises: forming the laminate after layering has been completed; wherein: forming the laminate comprises: placing the laminate between complementary forming tools; and drive the forming tools towards each other to form the laminate. 4. Method according to claim 2, further characterized by the fact that it comprises: acquiring images of tow placed by the AFP machine during layer formation (402); determining actual locations of tow placed by the AFP machine during layer formation based on the images (404); compare the actual tow locations with the expected tow locations indicated by the NC program (406); detect discrepancies between actual locations and expected locations (408); and changing the NC program during layering based on discrepancies (410). 5. Method according to claim 4, characterized by the fact that: a discrepancy comprises a gap between tows; and changing the NC program includes adding instructions for placing tow over the gap. 6. Method according to claim 4, characterized by the fact that: a discrepancy comprises a tow having an actual location that is a displacement from an expected location; and changing the NC program involves revising instructions for placing tow in other layers based on displacement. 7. Method according to claim 1, further characterized by the fact that it comprises: iteratively: simulating placement of features in the mandrel; generate a simulation forming a formation of laminate layers on the mandrel in 3D form; and change characteristics based on expected wrinkles or cracks indicated by the simulation. 8. Non-transitory computer-readable medium, characterized in that it incorporates programmed instructions that, when executed by a processor, are operable to perform a method comprising: placing features on a planar mandrel that permit a laminate formed in layers over the mandrel to compensate for restrictions corresponding to a three-dimensional (3D) shape during forming the laminate into the 3D shape (310); and generating a Numerical Control (NC) program that directs an Automated Fiber Laying (AFP) machine to layer the laminate, the NC program including instructions for layering tows of constituent material onto the planar mandrel, including the characteristics placed in the mandrel to form layers of the laminate (312); layering the laminate according to the NC program (352); and forming the laminate into 3D shape (354) loading data defining the 3D shape; identify constraints based on the dimensions of the 3D shape; flatten the 3D shape to a planar shape; and manufacturing the mandrel according to the planar shape. 9. Means according to claim 8, characterized by the fact that the method further comprises: placing the laminate between complementary forming tools; and trigger the forming tools toward each other during modeling. 10. System for generating a formation of layers of a laminate, characterized by the fact that it comprises: a memory (214) that stores data (216) defining a three-dimensional (3D) shape for a composite part; and a controller (212) that loads the data, identifies constraints based on the dimensions of the 3D shape, flattens the 3D shape to a planar shape (620), and places features (710) on the planar shape that allow for laminate layer formation. (240) compensate for constraints during forming the laminate into 3D shape, the controller generates a Numerical Control (CN) program (218) that directs an Automated Fiber Placement (AFP) machine (100) to layer the laminate, the NC program including instructions for forming layers of tow (244) of constituent material to form layers (242) of the laminate. 11. System according to claim 10, characterized by the fact that: the characteristics include changes to a surface of a flat mandrel on which the laminate is formed in layers. 12. System according to claim 10 or 11, characterized by the fact that: the features include tows (244) that are directed within a layer (242) of the laminate to increase an amount of material in the laminate. 13. System according to claim 10, 11 or 12 characterized by the fact that: the controller adds the characteristics by predicting a quantity of distance (L0-LI) by which a portion of the planar shape will expand during formation, and adds tow length to the planar shape corresponding to the quantity. 14. System according to claim 10, 11, 12 or 13, further characterized by the fact that it comprises: a camera (230) that acquires images (219) of tow (244) placed by the AFP machine during layer formation, in that the controller engages in a closed feedback loop comprising determining actual locations of tow placed by the AFP machine based on images, comparing actual tow locations with expected tow locations indicated by the NC program, detecting discrepancies between actual locations and the expected locations, and change the NC program during layering based on the discrepancies.