A design method for a two-dimensional and three-dimensional composite hybrid casing and layup structure

Abstract

The present invention discloses a two-dimensional and three-dimensional composite hybrid casing and a method for designing a layer structure, and relates to the field of composite material structure design and application technology. The present invention expands the structural cluster diversity of the hybrid casing, greatly increases the number of hybrid casing designs, and at the same time, the hybrid casing structure formed based on any of the above groups has better mechanical properties, and improves the structural crack arrest and anti-delamination capabilities by mixing two-dimensional composite materials with three-dimensional composite materials; provides a composite casing that uses a mixture of two-dimensional composite materials and three-dimensional composite materials, combining the advantages of the two composite materials, can increase the impact resistance of the casing, and improve the containment capacity, reduce weight, improve fuel efficiency, reduce noise, and improve the efficiency of the entire machine.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material structure design and application, and in particular to a two-dimensional and three-dimensional composite material hybrid casing and a layer structure design method. Background Art

[0002] Fiber-reinforced composites are replacing metal in aircraft engine casings. Currently, many newly developed high-performance, high-bypass ratio aircraft engines utilize fiber-reinforced polymer composites (FRP) for their casings. With the continuous optimization of casing materials and structural designs, a variety of composite casing structures have been developed. Two-dimensional fiber-reinforced composites are widely used in casing structures due to their excellent strength and stiffness. The GEnx engine's two-dimensional triaxially woven fiber-reinforced composite casing is a typical example. However, conventional two-dimensional composite structures suffer from poor interlaminar performance and are prone to delamination and large-scale crack propagation upon impact. Three-dimensional composite structures, however, effectively resist impact delamination due to fiber reinforcement in the thickness direction. Subsequently, improvements to three-dimensional weaving processes led to their application in casing structures such as the LEAP engine. While three-dimensional woven composites exhibit excellent resistance to crack initiation and propagation, the introduction of binder yarns reduces stiffness and strength, significantly weakening their containment capacity and reducing their resistance to foreign object impact. Achieving performance and structural optimization improvements in various composite materials, enhancing the containment capacity of composite casings while also improving their resistance to delamination and damage, has become a key research topic in the optimized design of composite containment casing structures. However, no research has addressed the hybrid layup of two- and three-dimensional composite structures. In summary, current research has not addressed the hybrid layup method for designing engine containment casings using two- and three-dimensional composite structures. Summary of the Invention

[0003] In response to the above-mentioned deficiencies in the prior art, the present invention provides a two-dimensional and three-dimensional composite hybrid casing and layup structure design method, which solves the problems that the prior art does not combine two-dimensional fiber composite materials and three-dimensional fiber composite materials, cannot solve the problems that the conventional structural interlayer performance of two-dimensional fiber composite materials is poor, and the three-dimensional fiber composite materials have weak resistance to foreign object impact and low containment capacity.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] A two-dimensional and three-dimensional composite material hybrid casing is provided, wherein the hybrid casing is an annular casing; the total number of casing layers of the annular casing is Layers, including Layers of two-dimensional composite materials and layers of three-dimensional composite material, and ;in:

[0006] The structural types of the two-dimensional composite material layers are all different;

[0007] The structural types of the three-dimensional composite material layers are all different;

[0008] The two-dimensional composite material layer and the three-dimensional composite material layer are mixed and laid according to a preset ratio.

[0009] Furthermore, the structural type of the two-dimensional continuous fiber composite material of each two-dimensional composite material layer is different; the structural types of the tow and the fabric include unidirectional ply, spread weave, twill weave and twill multi-axial weave.

[0010] Furthermore, the three-dimensional continuous fiber composite material of each three-dimensional composite material layer is different; the three-dimensional continuous fiber composite material includes a tow, a fabric, a three-dimensional four-directional braided composite material and a three-dimensional multi-directional braided composite material.

[0011] Furthermore, The thickness of the corresponding layers of the two-dimensional composite material are all different; The layer thicknesses corresponding to the three-dimensional composite material layers are different.

[0012] Furthermore, the mixed ply methods include The corresponding calculation formula is:

[0013] .

[0014] Furthermore, if each of the two-dimensional composite material layers adopts the same structural type, and each of the three-dimensional composite material layers adopts the same structural type, then the mixed layering method has The corresponding calculation formula is:

[0015] .

[0016] A method for designing a ply structure is provided, comprising the following steps:

[0017] S1. Determine the number of layers of the two-dimensional composite material and thickness ;

[0018] S2. Determine the number of layers of the three-dimensional composite material and thickness ;

[0019] S3. Calculate the total number of layers of the mixed casing and total thickness ;

[0020] S4. Selecting materials and structural types for each two-dimensional composite material layer and each three-dimensional composite material layer based on the properties of the two-dimensional continuous fiber material and the three-dimensional continuous fiber material and in combination with actual needs;

[0021] S5, based on the total number of layers of the casing , total thickness and thickness 、 , calculate the hybrid layup method of each composite material layer of the hybrid casing;

[0022] S6. Stack and mix the two-dimensional composite material layers and the three-dimensional composite material layers according to a preset ratio and mixing method.

[0023] The beneficial effects of the present invention are:

[0024] The present invention expands the diversity of structural clusters of composite material casings and greatly increases the number of designs of composite material casings. At the same time, the composite casing structure formed based on any of the above groups has better mechanical properties, and the three-dimensional composite material structure is mixed with the two-dimensional composite material to improve the structural crack arrest and anti-delamination capabilities; a composite material casing is provided, which is mixed with two-dimensional composite materials and three-dimensional composite materials, and combines the advantages of the two composite materials to increase the impact resistance of the casing, and improve the containing capacity, reduce weight, improve fuel efficiency, reduce noise and improve the efficiency of the whole machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of two-dimensional and three-dimensional composite casing structures;

[0026] Figure 2 Schematic diagram of the cross section of the two-dimensional and three-dimensional composite casing;

[0027] Figure 3 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0029] like Figure 1 and Figure 2 As shown, a two-dimensional and three-dimensional composite material hybrid casing is an annular casing; the total number of casing layers of the annular casing is Layers, including Layers of two-dimensional composite materials and layers of three-dimensional composite material, and ;in:

[0030] The structural types of the two-dimensional composite material layers are all different;

[0031] The structural types of the three-dimensional composite material layers are all different;

[0032] The two-dimensional composite material layer and the three-dimensional composite material layer are mixed and laid according to a preset ratio.

[0033] The structural type of the two-dimensional continuous fiber composite material of each two-dimensional composite material layer is different; the two-dimensional continuous fiber composite material includes tows and fabrics; the structural types of the tows and fabrics include unidirectional lay-up, spread weaving, twill weaving and twill multi-axial weaving.

[0034] The three-dimensional continuous fiber composite material of each three-dimensional composite material layer is different; the three-dimensional continuous fiber composite material includes a tow, a fabric, a three-dimensional four-directional braided composite material and a three-dimensional multi-directional braided composite material.

[0035] Two-dimensional continuous fiber composites and three-dimensional continuous fiber composites are a general term for composite materials reinforced by textiles that are continuously woven, woven, knitted and stitched, and are a new type of composite material. Among them, the fiber textile preform can be formed by impregnating it with resin. This material includes two-dimensional woven / textile composites and three-dimensional woven / textile composites. Two-dimensional woven composites are obtained by using a two-dimensional braid formed by warp and weft as a reinforcement, which can be obtained after prepreg curing and molding. Three-dimensional woven composites use an integral woven preform as a reinforcement material, and have high strength, stiffness, and good impact resistance and ablation resistance in the vertical direction. At the same time, they overcome the shortcomings of traditional laminate composites that are easy to delaminate, sensitive to cracking, and have rapid damage expansion. Therefore, the combination of two-dimensional continuous fiber composites and three-dimensional continuous fiber composites can improve the impact resistance of the casing.

[0036] The thickness of the corresponding layers of the two-dimensional composite material are all different; The thickness of the three-dimensional composite material layers is different. The mixed layering methods are: The corresponding calculation formula is:

[0037] .

[0038] If each of the two-dimensional composite material layers adopts the same structural type, and each of the three-dimensional composite material layers adopts the same structural type, then the mixed layering method is The corresponding calculation formula is:

[0039] .

[0040] like Figure 3 As shown, a ply structure design method includes the following steps:

[0041] S1. Determine the number of layers of the two-dimensional composite material and thickness ;

[0042] S2. Determine the number of layers of the three-dimensional composite material and thickness ;

[0043] The method of step S1 is the same as that of step S2. Based on the mechanical properties, durability and other performance requirements of the application scenario, the basic performance indicators of the required two-dimensional composite materials and three-dimensional composite materials are analyzed; based on the basic performance indicators and the safety factor formulated according to the requirements, the initial number of layers of the two-dimensional composite material layer and the initial number of layers of the three-dimensional composite material layer are determined; the thickness of each material layer is specified, and the mechanical properties under the initial number of layers and the specified thickness are simulated using the finite element analysis method to obtain the corresponding simulation results; the number of layers of the two-dimensional composite material layer is determined based on the simulation results and thickness , the number of layers of three-dimensional composite materials and thickness .

[0044] S3. Calculate the total number of layers of the mixed casing and total thickness ; Use FEA and other tools to simulate the mechanical properties of the casing to ensure that it meets actual needs, and adjust the thickness of each layer according to the simulation results to optimize the structure.

[0045] Total thickness The formula is:

[0046]

[0047] in, represents the summation function, 、 Respectively represent The spatial coordinates of the two-dimensional composite material layer, The spatial coordinates of the three-dimensional composite material layers, represents the thickness of the 2D composite layer, Indicates the The thickness of the three-dimensional composite material layer.

[0048] If the thickness of the two-dimensional composite material layer and the three-dimensional composite material layer is the same, the total thickness The formula is:

[0049]

[0050] S4. According to the characteristics of the two-dimensional continuous fiber material and the three-dimensional continuous fiber material, combined with actual needs, select the materials and structural types of each two-dimensional composite material layer and each three-dimensional composite material layer; the two-dimensional and three-dimensional composite materials are not limited to structural forms, Different structural forms and Two-dimensional continuous fiber material with a thickness of Different structural forms and The three-dimensional continuous fiber material with a thickness of 10000mm can diversify the structural clusters of the casing, greatly increase the number of casing designs, and have better corresponding structural mechanical properties;

[0051] Existing simulation technology can be used to evaluate the selected two-dimensional continuous fiber materials and three-dimensional continuous fiber materials, and the two-dimensional continuous fiber materials and three-dimensional continuous fiber materials that meet the requirements are selected as the final selection results.

[0052] S5, based on the total number of layers of the casing , total thickness and thickness 、 , calculate the mixed layup method of each composite material layer of the hybrid casing; a mixed design can be carried out according to the actual functional requirements of the casing. If the structure is mainly load-bearing, the number or thickness of the two-dimensional composite material layers will be increased; for example, the number (or thickness) of two-dimensional composite material layers accounts for 60~80% of the total number (or thickness) of layers, which can appropriately improve the load-bearing capacity of the casing structure. At the same time, the remaining three-dimensional composite material layers can appropriately improve the delamination damage of the casing structure to ensure structural integrity; if the structure is mainly to contain internal blades and external impact objects, two-dimensional composite materials can be used for the upper and lower surfaces, and three-dimensional composite materials can be used for the middle layer, and the number (or thickness) of two-dimensional composite materials accounts for 60~80%; if the structure is mainly based on impact resistance and crack arrest properties, two-dimensional and three-dimensional composite materials can be staggered and stacked, and the number (or thickness) of two-dimensional composite materials accounts for 30~70%; in short, the mixed method of casing layers can be allocated according to actual needs, combined with the high load-bearing and penetration resistance of two-dimensional composite materials and the anti-delamination and crack arrest capabilities of three-dimensional composite materials to allocate the number of layers, layup sequence and stacking method.

[0053] S6. Lay and mix the two-dimensional composite material layers and the three-dimensional composite material layers according to a preset ratio and mixing method. The preset ratio is the ratio of the three-dimensional composite material layers to the total number of layers, and the setting range is 20% to 80%.

[0054] In one embodiment of the present invention, the thickness of the two-dimensional composite material layer is 1 mm, and the thickness of the three-dimensional composite material layer is 1.5 mm. Taking the ratio of the two-dimensional to three-dimensional composite material casing layers as 30:20, the total thickness of the casing is 30×1 mm+20×1.5 mm=60 mm. The corresponding layup method is shown in Table 1.

[0055] Table 1

[0056]

[0057] in, express Layer-by-layer stacking of two-dimensional composite materials, express When the three-dimensional composite material is stacked layer by layer, or It is omitted when it is 1. The subscript 5S means that the ply is mirrored and replicated 5 times.

[0058] In summary, the present invention expands the diversity of structural clusters of hybrid casings and greatly increases the number of designs of hybrid casings. At the same time, the hybrid casing structure formed based on any of the above groups has better mechanical properties, and the three-dimensional composite material structure is mixed with the two-dimensional composite material to improve the structural crack arrest and anti-delamination capabilities; a composite casing is provided, which is mixed with two-dimensional composite materials and three-dimensional composite materials. Combining the advantages of the two composite materials, it can increase the impact resistance of the casing, and improve the containing capacity, reduce weight, improve fuel efficiency, reduce noise, and improve the efficiency of the whole machine.

Claims

1. A two-dimensional and three-dimensional composite material hybrid casing, characterized by: The mixed casing is an annular casing; the total number of casing layers of the annular casing is Layers, including Layers of two-dimensional composite materials and layers of three-dimensional composite material, and ;in: The structural types of the two-dimensional composite material layers are all different; The structural types of the three-dimensional composite material layers are all different; The two-dimensional composite material layer and the three-dimensional composite material layer are mixed and laid according to a preset ratio; When the hybrid casing is mainly used for load-bearing, the number or thickness of the two-dimensional composite material layer accounts for 60-80%; When the hybrid casing is mainly used to contain internal blades and external impactors, the upper and lower surfaces of the hybrid casing are made of two-dimensional composite materials, and the middle layer is made of three-dimensional composite materials. The number or thickness of the two-dimensional composite materials accounts for 60-80%; When the hybrid casing is mainly characterized by impact resistance and crack arrest properties, two-dimensional composite material layers and three-dimensional composite material layers are stacked alternately, and the number or thickness of the two-dimensional composite material layers accounts for 30~70%.

2. The two-dimensional and three-dimensional composite hybrid casing according to claim 1, characterized in that: The structural type of the two-dimensional continuous fiber composite material of each two-dimensional composite material layer is different; the two-dimensional continuous fiber composite material includes a tow and a fabric; the structural types of the tow and the fabric include unidirectional ply, spread weaving, twill weaving and twill multi-axial weaving.

3. The two-dimensional and three-dimensional composite hybrid casing according to claim 1, characterized in that: The three-dimensional continuous fiber composite materials of each three-dimensional composite material layer are different; the three-dimensional continuous fiber composite materials include tows, fabrics, three-dimensional four-directional braided composite materials and three-dimensional multi-directional braided composite materials.

4. The two-dimensional and three-dimensional composite hybrid casing according to claim 1, characterized in that: described The thicknesses of the corresponding two-dimensional composite material layers are different; The layer thicknesses corresponding to the three-dimensional composite material layers are different.

5. The two-dimensional and three-dimensional composite hybrid casing according to claim 2, characterized in that: The mixed layering method includes The corresponding calculation formula is: 。 6. The two-dimensional and three-dimensional composite hybrid casing according to claim 5, characterized in that: If each of the two-dimensional composite material layers adopts the same structural type, and each of the three-dimensional composite material layers adopts the same structural type, then the mixed layering method is The corresponding calculation formula is: 。 7. A method for designing a laminate structure of a two-dimensional and three-dimensional composite hybrid casing according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Determine the number of layers of the two-dimensional composite material and thickness ; S2. Determine the number of layers of the three-dimensional composite material and thickness ; S3. Calculate the total number of layers of the mixed casing and total thickness ; S4. Selecting materials and structural types for each two-dimensional composite material layer and each three-dimensional composite material layer based on the properties of the two-dimensional continuous fiber material and the three-dimensional continuous fiber material and in combination with actual needs; S5, based on the total number of layers of the casing , total thickness and thickness 、 , calculate the hybrid layup method of each composite material layer of the hybrid casing; S6. Stack and mix the two-dimensional composite material layers and the three-dimensional composite material layers according to a preset ratio and mixing method.

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