Composite material damage analysis method, device, equipment and storage medium

Abstract

The present invention provides a composite material damage analysis method, apparatus, device, and storage medium. The method comprises: dividing a composite material unit cell into hexahedral units, obtaining coordinate information of nodes in each hexahedral unit cell; obtaining the fiber contour envelope surface equation of the composite material; and then obtaining the material properties of each of the hexahedral units; constructing a composite material unit cell model based on the coordinate information and material properties; obtaining the unit equilibrium equation of the unit cell model based on displacement load information and parameters of the composite material, then obtaining the overall equilibrium equation, and then obtaining the node displacements of the unit cell model; obtaining simulation calculation results based on the node displacements, and updating the stiffness matrix and unit constitutive relations in the unit cell model based on the simulation calculation results. The present invention significantly simplifies the composite material modeling process, reduces the modeling difficulty, and does not require the use of commercial software or secondary development, significantly improving the efficiency of composite material damage analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material analysis, and in particular to a composite material damage analysis method, device, equipment and storage medium. Background Art

[0002] Fiber reinforced composite materials are widely used in various industrial fields due to their advantages such as high specific strength, large specific modulus, impact resistance, designable performance and easy forming. With the improvement of computing power, mechanical simulation of fiber materials can better verify the mechanical properties of the composite materials. Studying and analyzing the deformation and damage failure process of fiber reinforced composite materials after being subjected to stress is of great significance to improving the structure of composite materials and can also provide guarantees for the normal operation of aircraft in the working environment. Since the damage process of fiber reinforced composite materials after damage is relatively complex, it is difficult to accurately describe the damage process such as fiber breakage, matrix cracking and delamination between sublayers between different components and different materials through simulation analysis at the macro scale. Therefore, it is necessary to conduct micro-scale simulation analysis at the mechanical level.

[0003] However, the current finite element analysis method for composite material damage has many shortcomings. On the one hand, due to the complex orientation of fibers in the matrix and the complex modeling process, how to establish a fast, efficient and easy-to-converge model is the primary issue in composite material simulation. On the other hand, existing finite element software cannot directly perform damage analysis on composite materials. Finite element implementation requires secondary development with the help of commercial software, which is inconvenient to use, has a long execution cycle and low efficiency. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a composite material damage analysis method, device, equipment and storage medium.

[0005] In a first aspect, the present invention provides a composite material damage analysis method, comprising the following steps:

[0006] Dividing the composite material unit cell into hexahedral units of uniform size, and obtaining coordinate information of each node in each of the hexahedral units;

[0007] According to the actual situation of the composite material, obtaining the fiber profile envelope surface equation of the composite material;

[0008] Obtaining material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0009] constructing a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0010] According to the actual load conditions, the displacement load information of each node in the unit cell model is obtained;

[0011] Obtaining parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material;

[0012] Obtaining an overall equilibrium equation of the unit cell model according to the unit equilibrium equation of the unit cell model;

[0013] Obtaining node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0014] According to the node displacement, the simulation calculation results of the unit cell model are obtained, and the stiffness matrix and unit constitutive relationship in the unit cell model are updated according to the simulation calculation results.

[0015] Preferably, obtaining the fiber profile envelope surface equation of the composite material according to the actual situation of the composite material includes:

[0016] According to the fiber weaving method and fiber volume ratio of the composite material, the fiber contour envelope surface equation of the composite material is obtained.

[0017] Preferably, obtaining the material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation includes:

[0018] Obtaining the coordinates of the center of gravity of the hexahedral unit according to the coordinate information of each node of the hexahedral unit;

[0019] Determining whether the centroid coordinates of the hexahedral unit are located within the envelope surface defined by the fiber contour envelope surface equation;

[0020] If the center of gravity coordinates of the hexahedral element are located within the envelope surface, then the hexahedral element is a fiber material property;

[0021] If the center of gravity coordinates of the hexahedral element are not located within the envelope surface, the hexahedral element is a matrix material property.

[0022] Preferably, the obtaining of the parameters of the composite material, obtaining the unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material, includes:

[0023] Obtaining the parameters of the composite material, wherein the parameters include matrix parameters and fiber parameters, the matrix parameters include density, elastic modulus, Poisson's ratio, tensile strength and compressive strength, and the fiber parameters include density, Young's modulus, shear modulus, Poisson's ratio, tensile strength, shear strength, matrix damage-related constants and fiber damage-related parameters;

[0024] Obtaining a unit stiffness matrix of each of the hexahedral units according to the parameters of the composite material;

[0025] Obtaining a load vector of each of the hexahedral units according to the displacement load information;

[0026] Obtaining the unit equilibrium equation according to the unit stiffness matrix and the load vector;

[0027] Among them, the hexahedral unit includes a matrix material unit, a fiber material unit and an interface unit. The matrix material unit adopts an isotropic constitutive model, and the damage judgment adopts the maximum stress damage criterion. The fiber material unit adopts a transversely isotropic constitutive model, and the damage judgment adopts the Hashin criterion. The interface unit adopts a cohesive constitutive model, and the damage judgment adopts the BK damage criterion.

[0028] Preferably, obtaining the simulation calculation results of the unit cell model according to the node displacement, and updating the stiffness matrix and unit constitutive relationship in the unit cell model according to the simulation calculation results, includes:

[0029] Obtaining the integration point strain according to the node displacement;

[0030] Obtaining the integration point stress according to the integration point strain;

[0031] determining whether the hexahedral unit is damaged according to the integration point strain, the integration point stress, and a damage criterion of each of the hexahedral units in the composite material;

[0032] If damage occurs, the damage factor of the hexahedral unit is obtained, and the stiffness matrix and the unit constitutive relationship in the unit cell model are updated according to the damage factor.

[0033] Preferably, the obtaining of the parameters of the composite material, obtaining the unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material, includes:

[0034] Obtaining parameters of the composite material, performing iterative calculations based on the displacement load information and the parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model;

[0035] After obtaining the calculation results of the node reaction force, strain stress and damage of the unit cell model according to the node displacement, and updating the stiffness matrix and unit constitutive relationship in the unit cell model according to the damage, the method further includes:

[0036] Determine whether the iterative calculation is completed;

[0037] If the iterative calculation is completed, the simulation calculation result is output;

[0038] If the iterative calculation is not completed, the iterative step size is increased, the parameters of the composite material are re-acquired, and the iterative calculation is performed according to the displacement load information and the parameters of the composite material to obtain the unit equilibrium equation of the unit cell model.

[0039] Preferably, the calculation results include basic quantity displacement calculation results, derived quantity node reaction force calculation results, strain calculation results, stress calculation results and damage settlement results;

[0040] If the iterative calculation is completed, the calculation results are output, including:

[0041] If the iterative calculation is completed, the basic displacement calculation result, the derived node reaction force calculation result, the strain calculation result, the stress calculation result and the damage calculation result are output.

[0042] In a second aspect, the present invention provides a composite material damage analysis device, comprising:

[0043] A coordinate information acquisition module, used to divide the composite material unit cell into hexahedral units of uniform size and obtain the coordinate information of each node in each hexahedral unit;

[0044] An envelope surface acquisition module, used to obtain the fiber profile envelope surface equation of the composite material according to the actual situation of the composite material;

[0045] A material property determination module, configured to obtain the material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0046] a unit cell model construction module, configured to construct a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0047] A displacement load acquisition module is used to obtain the displacement load information of each node in the unit cell model according to the actual load condition;

[0048] a unit balance equation acquisition module, configured to acquire parameters of the composite material, and to acquire a unit balance equation of the unit cell model according to the displacement load information and the parameters of the composite material;

[0049] An overall balance equation acquisition module, configured to acquire the overall balance equation of the unit cell model according to the unit balance equation of the unit cell model;

[0050] a node displacement acquisition module, configured to acquire the node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0051] A calculation module is used to obtain simulation calculation results of the unit cell model according to the node displacement, and to update the stiffness matrix and unit constitutive relationship in the unit cell model according to the simulation calculation results.

[0052] In a third aspect, the present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program is used to execute the composite material damage analysis method described above.

[0053] In a fourth aspect, the present invention provides a computer device comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the composite material damage analysis method described above when executing the computer program.

[0054] The composite material damage analysis method, device, equipment and storage medium provided by the present invention have the beneficial effect of uniformly dividing the composite material into hexahedral units and obtaining the fiber contour envelope surface equation according to the actual situation of the composite material, judging the material properties of each hexahedral unit according to the relationship between the centroid coordinates of the hexahedral unit and the envelope surface defined by the fiber contour including the surface equation, constructing a unit cell model of the composite material, and after completing the composite material modeling, obtaining the unit equilibrium equation of each hexahedral unit according to the sum parameters and displacement load information of the composite material, and then further assembling the unit equilibrium equation to obtain the overall equilibrium equation, obtaining the node displacement, and further obtaining the damage simulation calculation results to analyze the composite material damage. The method provided by the present invention can quickly model according to simple parameters set by the unit cell size, significantly simplifying the composite material modeling process and reducing the modeling difficulty. Moreover, the method provided by the present invention integrates a complete composite material finite element analysis method to predict damage to the composite material without the need for commercial software and secondary development, significantly improving the efficiency of composite material damage analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a diagram showing the application environment of the composite material damage analysis method according to an embodiment of the present invention;

[0056] Figure 2 Schematic diagram of the process of composite material damage analysis method according to an embodiment of the present invention;

[0057] Figure 3 This is a structural block diagram of a composite material damage analysis device according to an embodiment of the present invention;

[0058] Figure 4 This is a diagram of the internal structure of a computer device according to an embodiment of the present invention;

[0059] Figure 5 Schematic diagram of the grid structure of a composite material unit cell model in an embodiment of the present invention;

[0060] Figure 6 The displacement distribution cloud diagram of the composite material unit cell model in the embodiment of the present invention;

[0061] Figure 7 A stress distribution cloud diagram of a composite material unit cell model in an embodiment of the present invention;

[0062] Figure 8 The strain distribution cloud diagram of the composite material unit cell model in the embodiment of the present invention;

[0063] Figure 9 This is a damage distribution cloud diagram of the composite material unit cell model in an embodiment of the present invention;

[0064] Figure 10 Graph showing the tensile stress-strain curve of a composite unit cell model in an embodiment of the present invention. DETAILED DESCRIPTION

[0065] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0066] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0067] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0068] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0069] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0070] Figure 1 FIG. 1 is an application environment diagram of a composite material damage analysis method in an embodiment. Figure 1 The composite material damage analysis method is applied to a composite material damage analysis system. The composite material damage analysis system includes a terminal 110 and a server 120. Terminal 110 and server 120 are connected via a network. Terminal 110 can be a desktop terminal or a mobile terminal. The mobile terminal can be at least one of a mobile phone, a tablet computer, and a laptop computer. Server 120 can be implemented as a standalone server or a server cluster consisting of multiple servers.

[0071] like Figure 2 As shown, an embodiment of the present invention provides a composite material damage analysis method, comprising the following steps:

[0072] Step 210: Divide the composite material unit cell into hexahedral units of uniform size, and obtain coordinate information of each node in each hexahedral unit;

[0073] Step 220: obtaining a fiber profile envelope equation of the composite material according to the actual conditions of the composite material;

[0074] Step 230, obtaining the material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0075] Step 240: constructing a unit cell model of the composite material based on the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0076] Step 250: Obtain displacement load information of each node in the unit cell model according to actual load conditions;

[0077] Step 260: Obtain parameters of the composite material, and obtain a unit equilibrium equation of the unit cell model based on the displacement load information and the parameters of the composite material;

[0078] Step 270: Obtain the overall equilibrium equation of the unit cell model according to the unit equilibrium equation of the unit cell model;

[0079] Step 280: Obtaining node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0080] Step 290: Acquire simulation calculation results of the unit cell model according to the node displacement, and update the stiffness matrix and unit constitutive relationship in the unit cell model according to the simulation calculation results.

[0081] Figure 2 FIG. 1 is a flow chart of a composite material damage analysis method according to an embodiment. It should be understood that although Figure 2 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 2 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily performed at the same time, but can be performed at different times. The order of execution of these sub-steps or stages is not necessarily one by one, but can be performed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0082] In step 210, the sides of the composite material unit cell are divided into equal parts into hexahedral units of uniform size. The eight nodes corresponding to each hexahedral unit are numbered according to the numbering rules of nodes and units, and the coordinate information of each node in each hexahedral unit is obtained. This facilitates the subsequent rapid retrieval of corresponding unit numbers when distinguishing material properties based on the coordinate information, and also facilitates assembly based on the coordinate information.

[0083] In step 220, the fiber profile envelope equation of the composite material is obtained according to the fiber weaving method and fiber volume ratio of the composite material.

[0084] For example, the fiber can be regarded as a tubular structure with a constant cross-sectional shape. The equation of the elliptical cross section with the major semi-axis a and the minor semi-axis b on the xOz plane can be expressed by the first formula:

[0085] (x+L / 2) 2 (b / a) 2 +(z+H / 4) 2 =b 2 -L / 2≤x≤-L / 2+a

[0086] x 2 (b / a) 2 +(zH / 4) 2 =b 2 -a≤x≤a

[0087] (xL / 2) 2 (b / a) 2 +(z+H / 4) 2 =b 2 L / 2-a≤x≤L / 2

[0088] Where a is the major semi-axis of the elliptical cross section, b is the minor semi-axis of the elliptical cross section, L is the length and width of the composite unit cell, and H is the height of the composite material.

[0089] The change in the center of the elliptical cross section along the fiber direction is approximated as a trigonometric function, as shown in the second formula:

[0090]

[0091] Then, the surface equation of the 2D woven elliptical cross-section fiber is obtained as shown in the third formula:

[0092]

[0093] In step 230, the coordinates of the center of gravity of the hexahedral unit are obtained according to the coordinate information of each node of the hexahedral unit;

[0094] Determining whether the centroid coordinates of the hexahedral unit are located within the envelope surface defined by the fiber contour envelope surface equation;

[0095] If the center of gravity coordinates of the hexahedral element are located within the envelope surface, then the hexahedral element is a fiber material property;

[0096] If the center of gravity coordinates of the hexahedral element are not located within the envelope surface, the hexahedral element is a matrix material property.

[0097] In step 240 , a unit cell model of the composite material can be constructed based on the coordinate information and material properties of each hexahedral unit for subsequent damage analysis.

[0098] The composite material unit cell model construction method provided by the embodiment of the present invention can quickly build a model by setting simple parameters according to the unit cell size, simplifying the complexity of composite material modeling and reducing the modeling difficulty. In addition, the unit cell model constructed by this method is easier to solve in the subsequent damage analysis process and has higher convergence calculation efficiency.

[0099] In step 250, displacement load information of each node in the unit cell model is obtained according to actual load conditions, wherein the actual load conditions include tension, compression, bending, torsion and shear.

[0100] Through the actual load conditions, the displacement load information of each node can be obtained, and the displacement load information can be used to construct the unit equilibrium equation.

[0101] In step 260, the parameters of the composite material are obtained, wherein the parameters include matrix parameters and fiber parameters, the matrix parameters include density, elastic modulus, Poisson's ratio, tensile strength and compressive strength, and the fiber parameters include density, Young's modulus, shear modulus, Poisson's ratio, tensile strength, shear strength, matrix damage-related constants and fiber damage-related parameters;

[0102] Obtaining a unit stiffness matrix of each of the hexahedral units according to the parameters of the composite material;

[0103] Obtaining a load vector of each of the hexahedral units according to the displacement load information;

[0104] According to the unit stiffness matrix and the load vector, the unit equilibrium equation is obtained, and the unit equilibrium equation is shown in the fourth formula:

[0105] Ke*U=Fe;

[0106] Among them, Ke represents the element stiffness matrix, U represents the element node displacement, and Fe represents the load vector.

[0107] The hexahedral unit includes a matrix material unit, a fiber material unit and an interface unit. The matrix material unit adopts an isotropic constitutive model. The damage judgment adopts the maximum stress damage criterion. The maximum stress damage criterion is described by the fifth formula:

[0108]

[0109] The fiber material unit adopts a transversely isotropic constitutive model, and the damage judgment adopts the Hashin criterion, which is described by the sixth formula:

[0110]

[0111]

[0112]

[0113] The interface unit adopts the cohesive constitutive model, and the damage judgment adopts the BK damage criterion. The BK criterion is described by the seventh formula:

[0114]

[0115] Among them, are the fracture energies under the corresponding modes, and G S = Gs + Gt , G T =G n +G S .

[0116] In steps 270-280, the unit equilibrium equations are assembled into an overall equilibrium equation, so that the final nodal displacement can be finally solved; the nodal displacement of the unit cell model is obtained according to the overall equilibrium equation of the unit cell model, and the obtained nodal displacement can be used for subsequent calculations.

[0117] In step 290, the simulation calculation results of the unit cell model are obtained according to the node displacement, and the stiffness matrix and unit constitutive relationship in the unit cell model are updated according to the simulation calculation results; wherein the simulation calculation results include node reaction calculation results, strain calculation results, stress calculation results and damage calculation results.

[0118] Specifically, the method includes the following steps:

[0119] Obtaining the integration point strain according to the node displacement;

[0120] Obtaining the integration point stress according to the integration point strain;

[0121] determining whether the hexahedral unit is damaged according to the integration point strain, the integration point stress, and a damage criterion of each of the hexahedral units in the composite material;

[0122] If damage occurs, obtaining a damage factor of the hexahedral unit, and updating the stiffness matrix and the unit constitutive relationship in the unit cell model according to the damage factor;

[0123] If no damage occurs, proceed directly to the next step.

[0124] Furthermore, the process of updating the stiffness matrix and unit constitutive relation in the unit cell model according to the damage factor can be expressed by the eighth to twelfth formulas:

[0125] The damage stiffness matrix of the matrix material is shown in the eighth formula:

[0126]

[0127] Among them, d m is the damage factor obtained using the maximum stress damage criterion;

[0128] The fiber material adopts an exponential stiffness degradation model, and the damage factor evolution formula is shown in the ninth formula:

[0129]

[0130]

[0131]

[0132] The damage stiffness matrix of fiber material is shown in the tenth formula:

[0133]

[0134] Among them, d1, d2, and d3 are fiber damage factors;

[0135] The definition of the interface damage evolution coefficient D is shown in the eleventh formula:

[0136]

[0137] in, To calculate the maximum value of equivalent separation displacement during loading;

[0138] When damage is triggered, the stiffness coefficient of the interface element is reduced, as shown in the twelfth formula:

[0139] K d =(1-D)K;

[0140] In one embodiment, in step 260, the parameters of the composite material are obtained, and an iterative calculation is performed based on the displacement load information and the parameters of the composite material to obtain the unit equilibrium equation of the unit cell model; accordingly, after step 290, the method further includes:

[0141] Determine whether the iterative calculation is completed;

[0142] If the iterative calculation is completed, the simulation calculation result is output;

[0143] If the iterative calculation is not completed, the iterative step size is increased and step 260 is executed again.

[0144] Among them, the output simulation calculation results include the basic displacement calculation results, the derived node reaction force calculation results, the strain calculation results, the stress calculation results and the damage settlement results. The simulation calculation results are output in the form of text files. The output formats include vtk format and res format, which are suitable for various post-processing interfaces.

[0145] It should be noted that whether the iterative calculation ends is determined based on whether the iteration converges or whether the iteration cycle is completed.

[0146] In order to perform the steps in the above embodiment and various optional embodiments, as Figure 3 As shown, another embodiment of the present invention provides a composite material damage analysis device, comprising:

[0147] A coordinate information acquisition module 310 is used to divide the composite material unit cell into hexahedral units of uniform size and obtain the coordinate information of each node in each hexahedral unit;

[0148] The envelope surface acquisition module 320 is used to obtain the fiber profile envelope surface equation of the composite material according to the actual situation of the composite material;

[0149] A material property determination module 330 is configured to obtain the material property of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0150] a unit cell model construction module 340 for constructing a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0151] The displacement load acquisition module 350 is used to obtain the displacement load information of each node in the unit cell model according to the actual load condition;

[0152] A unit balance equation acquisition module 360 is used to acquire parameters of the composite material, and acquire the unit balance equation of the unit cell model according to the displacement load information and the parameters of the composite material;

[0153] A global balance equation acquisition module 370 is configured to acquire the global balance equation of the unit cell model according to the unit balance equation of the unit cell model;

[0154] A node displacement acquisition module 380 is configured to acquire the node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0155] The calculation module 390 is used to obtain the simulation calculation results of the unit cell model according to the node displacement, and update the stiffness matrix and unit constitutive relationship in the unit cell model according to the simulation calculation results.

[0156] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are performed:

[0157] Dividing the composite material unit cell into hexahedral units of uniform size, and obtaining coordinate information of each node in each of the hexahedral units;

[0158] According to the actual situation of the composite material, obtaining the fiber profile envelope surface equation of the composite material;

[0159] Obtaining material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0160] constructing a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0161] According to the actual load conditions, the displacement load information of each node in the unit cell model is obtained;

[0162] Obtaining parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material;

[0163] Obtaining an overall equilibrium equation of the unit cell model according to the unit equilibrium equation of the unit cell model;

[0164] Obtaining node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0165] According to the node displacement, the simulation calculation results of the unit cell model are obtained, and the stiffness matrix and unit constitutive relationship in the unit cell model are updated according to the simulation calculation results.

[0166] In one embodiment, when the processor executes the computer program, the processor further implements the steps of the above composite material damage analysis method.

[0167] Figure 4 The internal structure diagram of a computer device in one embodiment is shown. The computer device may be Figure 1 The terminal 110 (or server 120) in Figure 4As shown, the computer device includes a processor, a memory, a network interface, an input device, and a display screen connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor may implement a composite material damage analysis method. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor may implement a composite material damage analysis method. The display screen of the computer device may be a liquid crystal display or an electronic ink display screen. The input device of the computer device may be a touch layer covering the display screen, or may be a key, trackball, or touchpad provided on the computer device housing, or may be an external keyboard, touchpad, or mouse.

[0168] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0169] Dividing the composite material unit cell into hexahedral units of uniform size, and obtaining coordinate information of each node in each of the hexahedral units;

[0170] According to the actual situation of the composite material, obtaining the fiber profile envelope surface equation of the composite material;

[0171] Obtaining material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation;

[0172] constructing a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit;

[0173] According to the actual load conditions, the displacement load information of each node in the unit cell model is obtained;

[0174] Obtaining parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material;

[0175] Obtaining an overall equilibrium equation of the unit cell model according to the unit equilibrium equation of the unit cell model;

[0176] Obtaining node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model;

[0177] According to the node displacement, the simulation calculation results of the unit cell model are obtained, and the stiffness matrix and unit constitutive relationship in the unit cell model are updated according to the simulation calculation results.

[0178] In one embodiment, when the computer program is executed by a processor, the steps of the composite material damage analysis method are further implemented.

[0179] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0180] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the present invention. The experimental methods in the following examples where specific conditions are not specified are generally based on the conditions recommended by the manufacturer.

[0181] Example

[0182] 1.1. Divide the composite unit cell into hexahedral units of uniform size, number the eight nodes corresponding to each unit according to the node and unit numbering rule, and obtain the coordinate information of each node in each hexahedral unit;

[0183] 1.2. Obtain the fiber profile envelope equation of the composite material based on the fiber weaving method and fiber volume ratio of the composite material;

[0184] 1.3. Based on the coordinate information of each node of each hexahedral unit, the centroid coordinates of each hexahedral unit are obtained. Based on whether the centroid coordinates of each hexahedral unit are within the fiber contour envelope equation, the material properties of the hexahedral unit are determined. If the centroid coordinates of the hexahedral unit are within the envelope, the hexahedral unit has fiber material properties; if the centroid coordinates of the hexahedral unit are not within the envelope, the hexahedral unit has matrix material properties.

[0185] 1.4. Based on the coordinate information of each node of each hexahedral unit and the material properties, a unit cell model of the composite material is constructed. The schematic diagram of the unit cell model is as follows: Figure 5 As shown, the specifications are 2.5mm*2.5mm*0.35mm, the grid size is 0.05mm*0.05mm*0.05mm, the light gray part in the model is the matrix material, the dark gray part is the warp fiber material, and the black part is the weft fiber material;

[0186] 1.5. Set the boundary condition of the unit cell model to stretch in the x-direction, add periodic boundaries in the other directions, and obtain the displacement load information of the unit cell model;

[0187] 1.6. Obtain the parameters of the composite material. Add parameters to the unit cell model according to the parameters of the composite material. The parameters are shown in Table 1. The parameters of the matrix material include density ρ, elastic modulus E, Poisson's ratio v, tensile strength f tes and compressive strength f comp The parameters of the fiber material include density ρ, Young's modulus E in two directions of the transversely isotropic material 11 and E 22 , shear modulus G in two directions 12 and G 13 , Poisson's ratio v1 and v2 in two directions, tensile strength f in two directions tes11 and f tes22 , compressive strength in two directions f comp11 and f comp22 , shear strength in two directions f shear11 and f shear22 , matrix damage related constant G m and fiber damage related constant G f According to the parameters and displacement load information of the composite material, the unit equilibrium equation of the unit cell model is obtained. The parameters of the composite material are shown in Table 1.

[0188] Table 1 Parameters of composite materials

[0189]

[0190] 1.7. Assemble the unit equilibrium equations into the overall equilibrium equation, and further obtain the node displacement of the unit cell model based on the overall equilibrium equation;

[0191] 1.8. According to the node displacement, simulation calculation is performed to obtain the simulation calculation results of strain, stress and damage, and the displacement cloud map, stress cloud map, strain cloud map, damage cloud map and overall stress-strain curve under tensile load are output.

[0192] The simulation results are as follows Figure 6-10 As shown, Figure 6 is the displacement distribution cloud map, Figure 7 is the stress distribution cloud diagram, Figure 8 is the strain distribution cloud diagram, Figure 9 is the damage distribution cloud map, Figure 10 is the tensile stress-strain curve.

[0193] Figure 10 In the figure, the horizontal axis is the total strain, the vertical axis is the total stress, the slope of the first section of the curve is the equivalent modulus of the composite material, and the stress value at the extreme point of the curve is the strength of the composite material. Figure 10 It can be seen that the equivalent modulus of the composite material is 9500 MPa and the strength of the composite material is 148.4 MPa.

[0194] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite material damage analysis method, characterized in that: The following steps are involved: Dividing the composite material unit cell into hexahedral units of uniform size, and obtaining coordinate information of each node in each of the hexahedral units; According to the actual situation of the composite material, obtaining the fiber profile envelope surface equation of the composite material; Obtaining material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation; constructing a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit; According to the actual load conditions, the displacement load information of each node in the unit cell model is obtained; Obtaining parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material; Obtaining an overall equilibrium equation of the unit cell model according to the unit equilibrium equation of the unit cell model; Obtaining node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model; According to the node displacement, the simulation calculation results of the unit cell model are obtained, and the stiffness matrix and unit constitutive relationship in the unit cell model are updated according to the simulation calculation results.

2. The composite material damage analysis method according to claim 1, characterized in that: The step of obtaining the fiber profile envelope equation of the composite material according to the actual situation of the composite material includes: According to the fiber weaving method and fiber volume ratio of the composite material, the fiber contour envelope surface equation of the composite material is obtained.

3. The composite material damage analysis method according to claim 1, characterized in that: Obtaining material properties of each hexahedral unit according to the coordinate information of each node of each hexahedral unit and the fiber contour envelope surface equation, including: Obtaining the coordinates of the center of gravity of the hexahedral unit according to the coordinate information of each node of the hexahedral unit; Determining whether the centroid coordinates of the hexahedral unit are located within the envelope surface defined by the fiber contour envelope surface equation; If the center of gravity coordinates of the hexahedral element are located within the envelope surface, then the hexahedral element is a fiber material property; If the center of gravity coordinates of the hexahedral element are not located within the envelope surface, the hexahedral element is a matrix material property.

4. The composite material damage analysis method according to claim 1, characterized in that: The obtaining of the parameters of the composite material, and obtaining the unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material, includes: Obtaining the parameters of the composite material, wherein the parameters include matrix parameters and fiber parameters, the matrix parameters include density, elastic modulus, Poisson's ratio, tensile strength and compressive strength, and the fiber parameters include density, Young's modulus, shear modulus, Poisson's ratio, tensile strength, shear strength, matrix damage-related constants and fiber damage-related parameters; Obtaining a unit stiffness matrix of each of the hexahedral units according to the parameters of the composite material; Obtaining a load vector of each of the hexahedral units according to the displacement load information; Obtaining the unit equilibrium equation according to the unit stiffness matrix and the load vector; Among them, the hexahedral unit includes a matrix material unit, a fiber material unit and an interface unit. The matrix material unit adopts an isotropic constitutive model, and the damage judgment adopts the maximum stress damage criterion. The fiber material unit adopts a transversely isotropic constitutive model, and the damage judgment adopts the Hashin criterion. The interface unit adopts a cohesive constitutive model, and the damage judgment adopts the BK damage criterion.

5. The composite material damage analysis method according to claim 1, characterized in that: The step of obtaining a simulation calculation result of the unit cell model according to the node displacement, and updating a stiffness matrix and a unit constitutive relationship in the unit cell model according to the simulation calculation result, includes: Obtaining the integration point strain according to the node displacement; Obtaining the integration point stress according to the integration point strain; determining whether the hexahedral unit is damaged according to the integration point strain, the integration point stress, and a damage criterion of each of the hexahedral units in the composite material; If damage occurs, the damage factor of the hexahedral unit is obtained, and the stiffness matrix and the unit constitutive relationship in the unit cell model are updated according to the damage factor.

6. The composite material damage analysis method according to claim 1, characterized in that: The obtaining of the parameters of the composite material, and obtaining the unit equilibrium equation of the unit cell model according to the displacement load information and the parameters of the composite material, includes: Obtaining parameters of the composite material, performing iterative calculations based on the displacement load information and the parameters of the composite material, and obtaining a unit equilibrium equation of the unit cell model; After obtaining the calculation results of the node reaction force, strain stress and damage of the unit cell model according to the node displacement, and updating the stiffness matrix and unit constitutive relationship in the unit cell model according to the damage, the method further includes: Determine whether the iterative calculation is completed; If the iterative calculation is completed, the simulation calculation result is output; If the iterative calculation is not completed, the iterative step size is increased, the parameters of the composite material are re-acquired, and the iterative calculation is performed according to the displacement load information and the parameters of the composite material to obtain the unit equilibrium equation of the unit cell model.

7. The composite material damage analysis method according to claim 6, characterized in that: The calculation results include basic displacement calculation results, derived node reaction force calculation results, strain calculation results, stress calculation results and damage settlement results; If the iterative calculation is completed, the calculation results are output, including: If the iterative calculation is completed, the basic displacement calculation result, the derived node reaction force calculation result, the strain calculation result, the stress calculation result and the damage calculation result are output.

8. A composite material damage analysis device, characterized in that: include: A coordinate information acquisition module, used to divide the composite material unit cell into hexahedral units of uniform size and obtain the coordinate information of each node in each hexahedral unit; An envelope surface acquisition module, used to obtain the fiber profile envelope surface equation of the composite material according to the actual situation of the composite material; A material property determination module, configured to obtain the material properties of each of the hexahedral elements according to the coordinate information of each node of each of the hexahedral elements and the fiber contour envelope surface equation; a unit cell model construction module, configured to construct a unit cell model of the composite material according to the coordinate information of each node of each hexahedral unit and the material properties of each hexahedral unit; A displacement load acquisition module is used to obtain the displacement load information of each node in the unit cell model according to the actual load condition; a unit balance equation acquisition module, configured to acquire parameters of the composite material, and to acquire a unit balance equation of the unit cell model according to the displacement load information and the parameters of the composite material; An overall balance equation acquisition module, configured to acquire the overall balance equation of the unit cell model according to the unit balance equation of the unit cell model; a node displacement acquisition module, configured to acquire the node displacements of the unit cell model according to the overall equilibrium equation of the unit cell model; A calculation module is used to obtain simulation calculation results of the unit cell model according to the node displacement, and to update the stiffness matrix and unit constitutive relationship in the unit cell model according to the simulation calculation results.

9. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and the computer program is used to execute the composite material damage analysis method according to any one of claims 1 to 7.

10. A computer device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the composite material damage analysis method according to any one of claims 1 to 7 is implemented.

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