CN115008847A

CN115008847A - Three-dimensional composite plate shell structure, aircraft, wind power blade shell and manufacturing method

Info

Publication number: CN115008847A
Application number: CN202210517755.3A
Authority: CN
Inventors: 张长增
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-09-06

Abstract

The invention discloses a three-dimensional composite plate shell structure constructed by resin continuous phases, which can be used for a wind power blade, a cabin cover, a boat shell, an aircraft wing or a shell skin of a cabin, replaces a sandwich laminated structure, and provides a wind power blade case constructed by the structure. The three-dimensional composite plate shell structure is a hollow three-dimensional structure, and mainly depends on solid materials, namely resin nail columns and fiber reinforced resin grids distributed in a lattice manner to bear stress transfer between the first skin layer and the second skin layer. Resin nail columns and fiber reinforced resin grids are naturally formed in the dry-process layering and resin injection guiding processes, the structural concept of the three-dimensional composite plate shell is achieved, and the target requirements of three aspects of core rigidity, strength and skin bonding and connecting strength are met. Based on the designability of the three-dimensional plate shell structure, the bearing requirements of different parts of the large shell component can be met through structural parameter adjustment, the use of balsa wood core materials is avoided, the process is simplified, and the cost is reduced.

Description

Three-dimensional composite plate shell structure, aircraft, wind power blade shell and manufacturing method

Technical Field

The invention discloses a three-dimensional composite plate shell structure with a continuous phase resin matrix, which can be used as a shell skin of a wind power blade, a cabin cover skin, a hull shell skin and a shell skin of an airplane wing or a cabin, and provides the wind power blade constructed by the three-dimensional composite plate shell structure and a blade skin manufacturing method.

Background

The description is made for the moment by taking a horizontal axis wind turbine blade as an example. Along with the rapid development of offshore wind power, the single machine capacity is larger and larger, the length size of the blade exceeds 100m, the width of the blade exceeds 5m, the blade is essentially a hollow structure with a keel and a shell (called a covering), the keel is a main bearing structure, and the covering plays a role in guaranteeing an aerodynamic profile, transferring torque and stress. Despite the use of a sandwich skin construction for the blade skin shell, the large outer surface area still results in a mass of over 40 tons. Although such a lightweight and high-strength fiber-reinforced resin composite material is used with great success in the field of wind turbine blades, the quality risk and the manufacturing cost of the blades are increasingly important in the intense market competition, and the technical economy of pursuing products is an eternal topic.

Composite material blades are a complex technology, and relate to deep combination among structural design, materials and processes, which supplement each other. Optimized upgrading of blade technology can only be achieved by comprehensive global consideration. The structure of the existing blade technology can be simply described as a skin shell supported by a framework, and the existing blade technology is formed by adopting dry-method layering and resin flow guiding technologies. The shaped shell skin is designed as a sandwich structure. The existing sandwich skin structure is a simple structure formed by a first and a second fiber-reinforced resin skins and a foam core material, and mainly has defects in several aspects, namely, a secondary interface between the outer skin layer and the core material is obviously influenced by materials and processes, debonding and stripping failure is very easy to occur, and secondly, at least two core materials are adopted as sandwich materials, namely balsa wood and plastic foam, wherein the two materials have respective advantages and disadvantages, the balsa wood has a water-containing problem, naturally grown wood causes great performance discreteness, manual screening and repair treatment bring cost increase and various additional defects, and the cargo source is once tense to cause fluctuation of a supply chain; the foam sandwich of the synthetic material has high performance requirements, so that a few foam core materials meeting the requirements are developed, and the cost is high. Thirdly, in order to improve the ability of the flow guiding resin and the bonding ability with the skin layer, some grooves must be processed on the surface of the core material, but the grooves do not penetrate through the thickness of the core material to enable the hard resin block to be directly bonded with the first and second skin layers, in order to meet the laying deformation characteristic of the conformable curved surface of the material plate, some cracks must be cut into the rigid foam plate to enable the plate to be broken, and meanwhile, gauze is used to be connected along the plate surface to facilitate laying, so the processing and manufacturing of the foam plate are complex and the cost is high.

In the traditional sandwich composite material structure, the material characteristics are suddenly changed from the outer covering layer to the core body, and the discontinuity is very abstaining from the mechanical structure and is very easy to solve the problem. The structure to be created by the invention is a hollow structure which penetrates through the thickness direction of the plate shell and has continuous material performance, the apparent quality of the hollow structure is equivalent to that of a sandwich composite material plate structure, but the resin matrix penetrates through the outer skin layer to the core layer, and the continuity of the material and the performance of the resin matrix can bring a plurality of excellent service performance and structure performance.

In the prior art, large shell components including wind power blades and other aircrafts such as airplanes and ships and warships adopt the sandwich structure. The stress of the shells is complex, and besides the in-plane stress, distributed loads vertical to the curved surface of the shell, such as wind-load air pressure, water pressure and the like, are always added to the bending load of the shell, so that the properties of the core body for connecting two skin layers are more exquisite, and the requirements on shear strength, compression strength, tensile strength, modulus, quality and performance stability are extremely high.

Disclosure of Invention

The invention provides a novel three-dimensional plate shell structure, and the three-dimensional plate shell structure is popularized and applied to wind power blades, fans and boats. Meanwhile, a molding manufacturing method of the large member with the three-dimensional plate-shell structure is provided.

Composite sandwich structures are known, which are two-dimensional planar structures that are three-dimensional by lamination in the thickness direction. The sandwich structure is a light material structure which can bear the in-plane stress state in the use occasion of the plate shell. The core body is structurally characterized in that two thin-wall skin layers are arranged on the outer surface, the light core material is arranged in the middle of the outer surface, the interface between the outer surface layer and the light core material is bonded by an adhesive, the two outer surface layers have internal stress on bearing surfaces, the middle core body restrains the two skin layers to keep the parallel state to resist the buckling instability of the skin layers, and therefore the core body performance is the key for resisting the buckling instability of the skin layers.

The invention provides a new skin structure concept, namely a three-dimensional structure with a hollow middle part is constructed, which is superior to the existing sandwich laminating skin structure, and the concept is that a method is searched and constructed for forming a solid material connected with a first skin layer and a second skin layer, the solid material has the efficiency of a roof beam column and has the characteristic of nail columns vertically connected with the first skin layer and the second skin layer, and the fine nail columns are densely and hemp-distributed between the two skin layers. Therefore, the plate shell structure is still a porous structure, the solid part bears stress, and the hollow part can contain cheap light materials (such as polystyrene foam which is cheap and easy to obtain) for auxiliary forming, which is effective for the process. Such a core structure is a heterogeneous, apparently lightweight structure, equivalent in mass to a homogeneous foam, but should be superior in use performance.

The core of the invention is that a closed-cell foam core body similar to a sand mold for metal casting is used as an inner mold, through holes for pouring resin are constructed on the surface of the closed-cell foam core body in a dot matrix arrangement, and fiber reinforced materials are laid on the outer surface of the core body in a dry method, so that after resin is encapsulated and cured under the vacuum auxiliary condition, the two outer-coated skin layer fibers are closely, firmly and reliably connected together through the resin impregnated in the fibers and the cured resin in the through hole cavity of the foam plate. Therefore, the lattice pore canal on the closed-cell foam core plate surface is not only a runner but also a cavity for molding. When the foam body is removed, only pure resin 'studs' are arranged between the outer skin layers, and the resin studs equivalently replace the core material part in the original sandwich structure. The structure of the hollow feature is the three-dimensional plate shell structure of the invention.

The retention of the foam within the three-dimensional slab-shell structure is also an acceptable corollary given that the foam core used in the secondary casting does not adversely affect the performance properties of the final product.

Further, if it is desired to reinforce the strength of the connection between the skins, a grid of glass fiber reinforced resin equivalent to reinforcing ribs may be additionally constructed between the two skins. The method is that glass fiber bands are adhered to the periphery of a foam core plate with lattice holes, the core plate is prefabricated, large-area array laying on the curved surface of the shell is carried out by using the prefabricated member, generally, the width of the glass fiber bands is slightly larger than the thickness of the foam core plate, for example, exceeds 3-5mm, and therefore a folded edge of the glass fiber bands on the plane of the skin layer is formed, and the function of connecting the flange edge with the skin layer is achieved. When the layer structure is poured with resin, a reinforcing rib structure of glass fiber reinforced resin can be formed, and in the area enclosed by the grids of the glass fiber reinforced resin reinforcing rib, pure resin studs distributed in a lattice manner are connected with the outer skin layer. Here, glass fiber tape is the best choice for the reinforcing material, and plant fibers such as paper or synthetic organic fiber tape such as nonwoven fabric can also be chosen. The glass ribbon may be a woven ribbon or a chopped strand mat or a continuous mat. The glass fiber band can be fixed by using the quick-drying glue spraying, and also can be fixed by using a rubber band for hooping.

Further, the three-dimensional plate shell structure has the greatest advantage that designability is achieved, and any one or more of four main structural characteristic parameters of the outer skin layer thickness, the grid size, the lattice density of resin stud columns and the connection body thickness between the outer skin layers can be adjusted in a matching mode. Thus, when the large cantilever type spar member is used, three-dimensional plate shell structures with different characteristic parameters can be designed according to different parts.

In order to strengthen the connection strength between the resin nail column and the skin layer, the resin nail column can be poured into a dumbbell shape, and two ends of the resin nail column are connected with the outer skin layer like flanges.

The closed-cell foam filling body can be the most common and cheap and has stable process quality, is a flexible molded polystyrene (EPS) closed-cell foam plate, has the volume weight of 15-60 kg/cubic meter, and is provided with through hole cavities which are distributed in a dot matrix manner in the surface and run through along the thickness direction and are used for accommodating pure resin studs. A glass ribbon wrap may be applied around the perimeter of the moulded polystyrene (EPS) closed cell foam slab for forming a fibre reinforced resin grid. The polystyrene (EPS) closed cell foam slab is inherently flexible and can conform very easily to the curved surface of the shell under vacuum assisted pressure, thus eliminating the need for slotting and fragmenting the foam slab as in the rigid foams used in the prior art.

Although the use of a polystyrene (EPS) foam sheet is recommended, the use of a PVC foam sheet, a PET foam sheet, a polyurethane foam sheet, or the like increases the contribution rate to the structural strength in addition to the cost, and thus, does not exclude the use of other foam sheets.

It is emphasized here that because the closed cell foam panels also adhesively bond the first and second skin layers after resin infusion, and thus are also part of the shared load, the contribution to resisting buckling instability of the skin layers is not insignificant.

For the plate shell with too large size in the thickness direction, for example, when the thickness reaches more than 40mm, the design can be changed, a double-level three-dimensional plate shell structure is constructed, and the plate shell with the double-level three-dimensional plate shell structure is equivalent to the plate shell with the single-level plate shell structure which is overlapped together, so that the structural characteristic is that the middle fiber laying layer parallel to the curved surface of the skin is arranged, the core body part is divided, the height sizes of the pure resin studs and the fiber reinforced resin grids are shortened, and the stability is improved. The middle fiber layer can also be a substitute such as a prepreg glass fiber grid, a steel wire mesh and the like.

The single-level or double-level three-dimensional board shell structure is characterized in that the material continuity formed by the resin matrix penetrates through the whole thickness direction of the board shell from the skin layer → the core body → the skin layer, and the material continuity is embodied. The continuity of the material guarantees the reliability of the structure. Meanwhile, the structural strength and rigidity of the fiber reinforced resin reinforcing ribs and the resin nail columns are far higher than those of foam core materials in the traditional sandwich structure and are also better than those of balsa wood materials. Therefore, for a large shell with in-plane stress and bending load, the competence of the three-dimensional composite plate shell structure is always higher than that of the traditional sandwich structure.

The three-dimensional composite plate shell structure can be applied to wind power blades, airplanes and boats to form novel wind power blades, aircraft shells and boat shells. The forming and manufacturing method is that after dry-method layering, resin matrix is vacuum-injected, and the three-dimensional composite plate shell structure is directly constructed. The process is a process of laying materials by a dry method, vacuum-assisted guide resin impregnating fibers and curing and molding; the dry-method laying material comprises the following specific contents that in the first step, a first skin layer fiber laying layer is firstly completed in a blade mould, then a closed-cell foam filling body slab array layer is laid, and finally a second skin layer fiber laying layer is laid; the closed-cell foam filling body plate array layer is a mosaic array formed by spreading closed-cell foam filling body plates along the curved surface of the blade shell skin, wherein the closed-cell foam filling body plates are through hole cavities distributed in a lattice mode in the surface of the plate and in the thickness direction, and the periphery of the plate surface can be covered by glass fiber ribbons; after resin is injected, pure resin studs can be formed in the injection holes of the closed-cell foam filling body plates, fiber reinforced resin grids can be formed in the glass ribbon interval between the adjacent closed-cell foam filling body plates, and if the adjacent closed-cell foam filling body plates are in clear space, pure resin grids can be poured, which can be equivalent to the resin studs.

The prefabricated closed-cell foam filling body plate used in the laying process is a prefabricated foam plate, and the prefabrication method is to perform hot-nail punching or cold-state punching on the plate surface by adopting automatic equipment and perform glass ribbon welting on the periphery of the plate surface. The prefabricated closed-cell foam filling body plate can meet the requirement of an efficient layering process.

Apparently, the three-dimensional plate shell structure is similar to the sandwich structure in the prior art in appearance, but the principle and mechanism of bearing stress are completely different from the microscopic structure analysis. The thinking of the invention is more advanced.

Description of the figures and examples

FIG. 1 Prior Art Sandwich with fiber composite (simple planar laminate construction)

FIG. 2 is a typical anatomical structure of a single-layer three-dimensional composite board shell (fiberglass reinforced resin lattice surrounding pure resin studs distributed in a lattice)

FIG. 3 is a schematic diagram of a two-layer three-dimensional plate shell structure

FIG. 4 shows a prefabricated glass fiber tape-covered closed-cell foam filling body plate or a fiber-covered foam batten

FIG. 5 shows the model state (partially cut away) after dry layering of the three-dimensional plate-shell structure and before resin infusion by flow guidance

FIG. 6 shows a casing structure (half casing) of a wind turbine blade constructed by a three-dimensional plate casing structure in which resin is injected and cured

In fig. 1-6, 1-first skin, 2-second skin, 3-bond, 4-load bearing support, 5-closed cell foam filler, 6-pure resin stud, 7-fiber reinforced resin grid, 8-lightweight core, 9-mold, 10-pre-shell area, 11-mid-shell area, 12-post-shell area, 13-cap UD fiber preform, 14-trailing edge UD fiber lay-up, 15-pre-shell area three-dimensional composite board shell, 16-mid-shell area three-dimensional composite board shell, 17-post-shell area three-dimensional composite board shell, 18-fiberglass tape.

In the conventional sandwich panel shell illustrated in fig. 1, it is simple to include a first skin layer 1 and a second skin layer 2, and a light core material 8 in between, and the light core material 8 and the skin layers are bonded by adhesive bonding. The main defects are easy delamination, high cost and no designability, and the balsa wood has to be used in a heavy-load structure.

Fig. 2 is a typical three-dimensional composite shell structure of the present invention, which is macroscopically divided into three-dimensional composite shells having a first skin 1 and a second skin 2 and an intermediate connecting body 3. The connecting body 3 is composed of a bearing support body 4 and a closed-cell foam filling body 5, the bearing support body 4 is geometrically divided and surrounded by the closed-cell foam filling body 5 in space, and the bearing support body 4 penetrates through an interlayer space between the first and second skin layers in the thickness direction and is firmly connected with the first and second skin layers.

The lower diagram example of fig. 2 is a single level with the first skin layer cut away to show the internal structure. A typical reinforced structure is illustrated, but in practice there is a common structure with a core having only pure resin studs 6 and no fibre reinforced resin grids 7. The reference number 5 in the figure indicates the volume of space between the pure resin studs 6 and the fibre-reinforced resin grid 7.

As can be seen in fig. 2, the three-dimensional plate-shell structure is composed of three parts, namely a first skin layer 1 and a second skin layer 2 of fiber reinforced resin, and a connection body 3 between the curved surfaces of the first skin layer and the second skin layer, wherein the connection body 3 is composed of a bearing support body 4 and a closed-cell foam filling body 5, the bearing support body 4 is geometrically divided and surrounded in space by the closed-cell foam filling body 5, the bearing support body 4 penetrates through the interlayer space between the first skin layer and the second skin layer in the thickness direction and is firmly bonded with the first skin layer and the second skin layer, and is a stress transfer medium between the first skin layer and the second skin layer, and the closed-cell foam filling body 5 is only a molding auxiliary material and provides a pouring resin runner and a resin solidification cavity to play a role in separation; the bearing support body 4 is at least one of pure resin studs 6 and fiber reinforced resin grids 7 distributed in a lattice manner; the resin material in the first and second skins and the load-bearing support are identical, so that the resin is a continuous medium throughout the thickness of the shell.

The load bearing support 4 has a typical structure of a lattice of pure resin studs 6 surrounded by a lattice of glass fibre reinforced resin 7 of a wide range of sizes. The large-scale proposal is that the diameter of the resin pin column is preferably 2-5mm in the range of 100-500mm on a side. Preferably, the lattice density is 25-100 dots per square decimeter. The wall thickness of the fiberglass reinforced resin grid 7 is typically in the range of 2-5 mm.

Fig. 2 illustrates a conceptual diagram in which the pure resin studs 6 and the fiber-reinforced resin grids 7 may be combined in various configurations, and in extreme cases, only the pure resin studs 6 and no fiber-reinforced resin grids 7, or only the fiber-reinforced resin grids 7 and no pure resin studs 6. In addition, the pure resin stud 6 may be circular or bar-shaped. The fibre-reinforced resin grid 7 may also be a number of parallel spaced slats, not necessarily closed.

FIG. 3 is a schematic diagram of a double-layer three-dimensional plate shell structure with a heavy in-plane load, which is suitable for a plate shell with a large thickness and a heavy load, and the structure is provided with a middle fiber laying layer parallel to the curved surface of an outer covering, and a core body part is divided into two layers, so that the height dimensions of pure resin studs and fiber reinforced resin grids are shortened.

FIG. 4 shows a schematic diagram of a prefabricated closed-cell foam filling body panel with a glass ribbon covered edge, and only simple lattice opening is needed for manufacturing a common three-dimensional composite plate shell structure. The prefabricated closed-cell foam slab has dumbbell-shaped through holes perpendicular to the plane of the slab and penetrating the thickness direction, and is essentially a casting cavity mold. From such a mould, the three-dimensional plate shell structure required by the present invention can be cast. When the closed cell foam infill panel aspect ratio in fig. 4 is sufficiently significant, it is deformed into a continuous ribbon-edged closed cell foam infill strip.

The three-dimensional board shell structure dry process that fig. 5 illustrates is spread the layer back, the model state before the resin is poured in the water conservancy diversion, is a hair state, and essentially, the external mold of pouring die cavity is product mould 9 (like the blade mould), and the centre form of die cavity is then foretell prefabricated obturator foam plate. Such an inner mould may simply be left in the plate shell at the end. Through the supplementary water conservancy diversion resin in vacuum, the die cavity of pouring embedment pooh spare, the fibre in cortex and the grid wherein of abundant flooding, the design of three-dimensional composite board shell structure is obtained after the resin solidification.

In addition, the splicing structure of the prefabricated closed-cell foam plate determines the internal cavity configuration of the three-dimensional plate shell structure, and various splicing methods can be adopted in practice. If a clearance space is designed between two adjacent blocks, the space is a space die cavity, and after resin is injected, pure resin is formed, which is equivalent to a pure resin nail column. If the spacing is relied on, for example, by a prepreg fiberglass mesh plate, the grid bars of the pre-buried fiberglass mesh are poured. For another example, if the prefabricated closed-cell foam plate is constructed by wrapping glass cloth (or felt) around the outer part of a full-length closed-cell foam strip and the core body layers are formed after being arranged in parallel, after resin is injected, the fiber reinforced resin grid 7 can be obtained, and the cross section of the three-dimensional composite plate-shell structure looks like a row of parallel square tube sectional materials. The structure is very suitable for the fan blade, and the length direction of the poured square pipe is along the longitudinal direction of the blade.

Fig. 6 shows a case of a shell structure of a wind power blade constructed by a three-dimensional plate shell structure formed by half resin injection and curing, which is a horizontal axis wind power equipment blade. The finished blade is externally provided with a triangular pyramid framework consisting of an adsorption side UD beam cap, a compression side UD beam cap and a tail edge UD beam, and a skin structure shell attached to the framework, and a web plate for connecting the two beam caps is arranged in the blade. The three-dimensional composite shell structure of the present invention may be used in both the shell and web regions of the blade.

The shell skin structure, the web plate structure or both of the shell skin structure and the web plate structure are three-dimensional plate shell structures, namely, the shell skin structure is composed of a first skin layer and a second skin layer of fiber reinforced resin and a connecting body between curved surfaces of the first skin layer and the second skin layer, wherein the connecting body is composed of a bearing support body and a closed-cell foam filling body, the bearing support body is geometrically divided and surrounded by the closed-cell foam filling body in space, the bearing support body penetrates through an interlayer space between the first skin layer and the second skin layer in the thickness direction and is firmly bonded with the first skin layer and the second skin layer, the bearing support body is a stress transmission bearing part between the first skin layer and the second skin layer, and the closed-cell foam filling body is only a forming auxiliary material and plays roles in guiding a cavity and spacing; the bearing support body is at least one of pure resin studs 6 and fiber reinforced resin grids 7 distributed in a lattice manner; the resin materials in the first and second leather layers and the bearing support body are completely the same to form a continuous phase entity; the longitudinal length from the blade tip to the blade root is divided into a front shell area 10, a middle shell area 11 and a rear shell area 12, and the three-dimensional composite plate shell structure in the three areas can be adapted and adjusted in one or more of four main structure characteristic parameters including the thickness of a first skin layer and a second skin layer, the size of a grid, the lattice density of resin columns and the thickness of a connection body between the first skin layer and the second skin layer. The figure shows a three-dimensional composite plate shell 15 in a front shell area, which only has pure resin studs 6 and does not have fiber reinforced resin grids 7, a three-dimensional composite plate shell 16 in a middle shell area, which has the pure resin studs 6 and the fiber reinforced resin grids 7, only has the relatively sparse density of the fiber reinforced resin grids 7, and a three-dimensional composite plate shell 17 in a rear shell area, which has the pure resin studs 6 and the fiber reinforced resin grids 7, and has the relatively dense density.

Therefore, in the blade structure, a core body structure can be completely and uniformly used, only the core body structure parameters of different parts are different, and in addition, the dependence on the natural material balsa wood is completely eliminated.

The method for forming the three-dimensional composite plate shell structure blade comprises the steps of firstly laying a first skin layer 1 in a die 9, then presetting a spar cap UD fiber prefabricated part 13, then laying a front shell area three-dimensional composite plate shell 15 in a front shell area 10, laying a middle shell area three-dimensional composite plate shell 16 in a middle shell area 11, laying a front shell area three-dimensional composite plate shell 17 in a rear shell area 12, then laying a UD rear edge fiber laying layer 14, and finally laying a second skin layer 2. Thus, the dry layering is finished. Then covering a sealing film, and vacuumizing to form the injection guiding blank. The blank is then infused with resin under vacuum assist, which sets the blade (half shell) after curing. It is then necessary to sew the two half-shells and the web together to form a single blade and to carry out post-processing operations for other items.

The three-dimensional composite board shell is characterized in that prefabricated closed-cell foam plates constructed by sticking or wrapping glass cloth (or felt) on the outer parts of full-length closed-cell foam strips and core body laying layers formed after parallel arrangement are used for blade products, and after resin is introduced, fiber reinforced resin grids 7 can be obtained, and the cross section of the three-dimensional composite board shell structure looks like a row of parallel square-tube sectional materials. The tensile and compressive strength and modulus in the thickness direction from the adhesive strength were excellent. The through-length foam strips may also be perforated to allow for the opportunity to form resin studs 6, thereby increasing the flow directing characteristics of the overall housing. The application or wrapping of such fibres (yarn/cloth/tape/felt) by means of an automatic device, with closed-cell foam strips, is very simple, belonging to a continuous profile feature, and extremely inexpensive. The prefabricated cloth-wrapping foam strip is relatively flexible in the length direction and can meet the deformation characteristic of a curved surface laying layer.

In the layering of the blade, a beam cap keel and a prefabricated closed-cell foam plate are actually embedded, a first skin layer 1 is attached to a mold 9, a second skin layer 2 is attached to the uppermost surface of the blade, and a three-dimensional composite plate shell structure is formed and a combination of the blade keel and a shell skin is also formed at the same time through integral pouring of resin.

In conclusion, the resin studs 6 and the fiber reinforced resin grids 7 are naturally formed in the dry-process layering and resin injection processes, so that the structural concept of the three-dimensional composite plate shell is realized, and the target requirements of three aspects of core rigidity, strength and skin bonding and connecting strength are met. Based on the designability of the three-dimensional plate shell structure, the bearing use of different parts of a large shell component can be met through structural parameter adjustment, the trouble of using a plurality of core materials of balsa wood and foam is avoided, and the balsa wood is also a material which needs to be imported and is obviously restricted by a supply chain goods source, so that the process is simplified, and the cost is reduced.

The above description is only a specific example of the present invention and is not intended to limit the scope of the present invention.

Claims

1. A three-dimensional composite plate shell structure can be used as a structural skin, and is characterized by comprising a first skin layer 1 and a second skin layer 2 of fiber reinforced resin and a connection body 3 between curved surfaces of the first skin layer and the second skin layer, wherein the connection body 3 consists of a bearing support body 4 and a closed-cell foam filling body 5, the bearing support body 4 is geometrically divided and surrounded by the closed-cell foam filling body 5 in space, the bearing support body 4 penetrates through an interlayer space between the first skin layer and the second skin layer in the thickness direction and is firmly connected with the first skin layer and the second skin layer, the bearing support body is a stress transmission medium between the first skin layer and the second skin layer, and the closed-cell foam filling body 5 is a forming auxiliary material and provides a cavity for pouring a resin runner and solidifying the resin to form a resin nail column; the bearing support body 4 is at least one of pure resin studs 6 and fiber reinforced resin grids 7 distributed in a lattice manner; the resin materials in the first and second skin layers and the bearing support body are completely the same and continuous in medium.

2. The three-dimensional composite shell structure according to claim 1, wherein there is a typical structure in which the load-bearing support 4 is a lattice of pure resin studs 6 surrounded by a lattice of glass fiber reinforced resin 7 of a wide range of sizes.

3. A three-dimensional composite shell structure according to claim 1, wherein there is a typical structure in which the load bearing support 4 is a transverse array of fiberglass reinforced resin grids 7 extending longitudinally along the shell, a transverse array of fiber reinforced resin grids 7 obtained by building prefabricated closed cell foam slabs from a full length of foam strip externally wrapped with fiberglass cloth (or felt), laying the cores side by side to form a core lay-up, and infusing and curing the resin.

4. The three-dimensional composite shell structure of claim 1, wherein the shell having an excessively large dimension in the thickness direction is constructed in a two-stage three-dimensional composite shell structure having a centrally disposed fiber lay-up parallel to the outer skin curved surface, and the core portion is divided into two layers to shorten the height dimension of the pure resin studs and the fiber reinforced resin grids.

5. The three-dimensional composite shell structure of claim 1, wherein said closed-cell foam filling body is a flexible molded polystyrene (EPS) closed-cell foam slab having a bulk density in the range of 15-60 kg/cubic meter and through-going through-hole cavities in its plane having an array of dots running through its thickness for receiving the pure resin studs 6.

6. The three-dimensional composite shell structure according to claim 1 or 5, wherein the closed-cell foam infill 5 is surrounded by a glass ribbon, after resin infusion, forming a fiberglass reinforced resin grid 7.

7. A horizontal shaft wind power equipment blade is characterized in that the blade is externally provided with a triangular pyramid framework consisting of an adsorption side UD beam cap, a compression side UD beam cap and a tail edge UD beam, and a skin structure shell attached to the framework, and a web plate for connecting the two UD beam caps is arranged in the blade; the shell skin structure, the web plate structure or both of the shell skin structure and the web plate structure are three-dimensional composite plate shell structures, namely, the shell skin structure is composed of a first skin layer and a second skin layer of fiber reinforced resin, and a connecting body between curved surfaces of the first skin layer and the second skin layer, wherein the connecting body is composed of a bearing support body and a closed-cell foam filling body, the bearing support body is divided and surrounded by the closed-cell foam filling body in space geometry, the bearing support body penetrates through an interlayer space between the first skin layer and the second skin layer in the thickness direction and is firmly bonded with the first skin layer and the second skin layer, and is a stress transmission bearing part between the first skin layer and the second skin layer, the closed-cell foam filling body 5 is a molding auxiliary material and provides a casting resin runner and a cavity for forming a resin nail column by resin solidification; the bearing support body is at least one of pure resin nail columns and fiber reinforced resin grids which are distributed in a lattice manner; the resin materials in the first and second leather layers and the bearing support body are completely the same to form a continuous phase entity; and in the longitudinal length from the blade tip to the blade root, the three-dimensional composite plate shell structure can be adapted and adjusted in one or more of four main structure characteristic parameters, namely the thickness of the first and second skin layers, the grid size, the lattice density of resin nail columns and the thickness of a connecting body between the first and second skin layers.

8. A manufacturing and forming method of a three-dimensional composite plate shell structure on a wind power blade is characterized by comprising the technological processes of laying materials by a dry method, vacuum-assisted diversion resin impregnating fibers and curing and forming; the dry-method laying material comprises the following specific contents that in the first step, a first skin layer fiber laying layer is firstly completed in a blade mould, then a closed-cell foam filling body slab array layer is laid, and finally a second skin layer fiber laying layer is laid; the closed-cell foam filling body plate array layer is a mosaic array formed by spreading closed-cell foam filling body plates along the curved surface of the blade shell skin, wherein the closed-cell foam filling body plates are holes which are distributed in a lattice mode and penetrate through the thickness direction in the surface of the plate, and the periphery of the plate is provided with a glass ribbon bound edge; when the resin is infused, pure resin studs 6 are formed in the infusion holes of the closed cell foam infill panels, and a fibre reinforced resin grid 7 is formed in the space between the glass fibre tape between adjacent closed cell foam infill panels.

9. The method for manufacturing and shaping the three-dimensional composite board shell structure of the blade according to claim 8, wherein the prefabricated closed-cell foam filling body plate used in the laying process is a prefabricated foam plate or a foam strip covered with cloth, and the prefabrication method is to use an automatic device to perforate the plate surface and carry out glass ribbon binding or wrapping on the periphery of the plate strip.

10. A large-scale composite material member constructed by a three-dimensional composite plate shell structure comprises but is not limited to an aircraft cabin shell, a wind power cabin cover, a boat shell and the like, and is characterized in that a shell skin structure comprises three parts, namely a first skin layer and a second skin layer of fiber reinforced resin and a connection body between curved surfaces of the first skin layer and the second skin layer, wherein the connection body comprises a bearing support body and a closed-cell foam filling body, the bearing support body is divided and surrounded by the closed-cell foam filling body in space geometry, the bearing support body penetrates through an interlayer space between the first skin layer and the second skin layer in the thickness direction and is firmly bonded with the first skin layer and the second skin layer, the bearing support body is a stress transmission bearing part between the first skin layer and the second skin layer, and the closed-cell foam filling body is a forming auxiliary material and provides a pouring resin flow passage and a cavity for resin solidification to form a resin nail column; the bearing support body is at least one of pure resin nail columns and fiber reinforced resin grids which are distributed in a lattice manner; the resin materials in the first and second leather layers and the bearing support body are completely the same, and form a continuous phase solid medium.