Composite material failure prediction method suitable for different strain rates and related device

Abstract

The invention discloses a composite material failure prediction method suitable for different strain rates and a related device, and relates to the technical field of composite material failure prediction.The method comprises the steps that an initial mathematical model used for generating a composite material failure envelope line is constructed, and then a mechanical property experiment is conducted on a composite material at the preset strain rate; the preset strain rates comprise a strain rate under a static load, a strain rate under a quasi-static load and a strain rate under a dynamic load, determining the value of an unknown coefficient in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model, and generating a failure envelope line of the composite material by using the mathematical model. And determining the safety strength range of the composite material based on the failure envelope. According to the method, the failure of the composite material can be accurately predicted under different load conditions, and the problem of strength prediction of the composite material under the variable load condition in the current theory and application can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of composite material failure prediction, and in particular to a composite material failure prediction method and related devices applicable to different strain rates. Background Art

[0002] In recent years, the use of composite materials in structural design has increased significantly, ranging from quasi-static to dynamic loading conditions. This trend has brought new challenges to designers because composite materials exhibit nonlinear behavior and are strain rate dependent. As a result, the testing and design process of new composite structures has become very time-consuming and requires a lot of material resources, especially for large structures. In order to speed up and simplify the design process of composite structures, it becomes crucial to establish an effective and comprehensive method to predict the failure envelope of composite materials, which will enable designers to make informed decisions and optimize the design, ultimately reducing time and material costs.

[0003] Classical limit state failure criteria, such as Sun, Puck, Tsai-Wu and Hashin failure criteria, have been able to be used to describe experimental data obtained from quasi-static tests, producing varying degrees of consistency. However, the operating conditions experienced by composite materials require exploration of their behavior under time-dependent loads and dynamic influences, and current failure criteria have great limitations. The latest research on failure criteria has mainly focused on empirical numerical constitutive equations to predict mechanical behavior and perform computational analysis. Other researchers have proposed a new set of homogenized failure criteria, which is based on representative volume element analysis of computational micromechanics. Under multiaxial loading conditions, three main failure mechanisms or modes are identified, namely, tensile, shear and compression-dominated failure mechanisms. The formulas for these three main failure mechanisms are quite complex, and there is no description of the impact of dynamic loads on this failure criterion. Summary of the invention

[0004] The purpose of this application is to provide a composite material failure prediction method and related devices suitable for different strain rates, which can accurately predict the failure of composite materials under different load conditions and solve the strength prediction problem of composite materials under variable load conditions in current theory and application.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a composite material failure prediction method applicable to different strain rates, the composite material failure prediction method applicable to different strain rates comprising:

[0007] Constructing an initial mathematical model for generating composite material failure envelopes;

[0008] Obtaining mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under a static load, the strain rate under a quasi-static load, and the strain rate under a dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength, and shear strength;

[0009] Determining the values ​​of unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model;

[0010] The mathematical model is used to generate a failure envelope of the composite material, and a safe strength range of the composite material is determined based on the failure envelope; the safe strength range is used to design the structure of a component prepared based on the composite material.

[0011] Optionally, an initial mathematical model for generating a failure envelope of a composite material is constructed, specifically comprising:

[0012] Determine a mathematical formula for generating a composite material failure envelope based on a tensor-polynomial formula;

[0013] Taking into account the influence of strength anisotropy in the transverse direction, the mathematical formula is processed to obtain an initial mathematical model for generating a failure envelope of the composite material.

[0014] Optionally, the mathematical formula is:

[0015]

[0016] Among them, σ 2 is the normal stress perpendicular to the reinforcement direction of the composite material; τ 6 is the shear stress in the plane of the composite material; m, n, k are all unknown coefficients.

[0017] Optionally, the initial mathematical model is:

[0018]

[0019] Among them, σ 2 is the normal stress perpendicular to the reinforcement direction of the composite material; τ 6 is the shear stress in the plane of the composite material; m, n, k, and α are all unknown coefficients.

[0020] Optionally, m is calculated as:

[0021]

[0022] in, is the transverse tensile strength; is the transverse compressive strength;

[0023] The calculation formula of α is:

[0024]

[0025] The calculation formula for k is:

[0026]

[0027] in, is the normal stress corresponding to the shear strength; is the shear strength;

[0028] The calculation formula for n is:

[0029]

[0030] Optionally, generating a failure envelope of the composite material using the mathematical model, and determining a safety strength range of the composite material based on the failure envelope, specifically includes:

[0031] A plurality of normal stress values ​​are randomly selected within a preset value range; the minimum value of the preset value range is the transverse compression strength, and the maximum value of the preset value range is the transverse tensile strength;

[0032] For each value of normal stress, the value of normal stress is used as input, the value of shear stress is determined using the mathematical model, and the value of normal stress and the value of shear stress are combined into one data point;

[0033] Taking the normal stress as the x-axis and the shear stress as the y-axis, all the data points are connected to obtain the failure envelope of the composite material;

[0034] The area formed by the failure envelope, the x-axis and the y-axis is taken as a safe area, and the values ​​of the normal stress and the shear stress within the safe area constitute the safe strength range of the composite material.

[0035] In a second aspect, the present application provides a composite material failure prediction device applicable to different strain rates, the composite material failure prediction device applicable to different strain rates comprising:

[0036] a model building module for building an initial mathematical model for generating a failure envelope of a composite material;

[0037] A parameter acquisition module, used to acquire mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under a static load, the strain rate under a quasi-static load, and the strain rate under a dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength, and shear strength;

[0038] A model generation module, used to determine the values ​​of unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model;

[0039] A failure prediction module is used to generate a failure envelope of the composite material using the mathematical model, and determine a safe strength range of the composite material based on the failure envelope; the safe strength range is used to design the structure of a component prepared based on the composite material.

[0040] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described methods for predicting composite material failures applicable to different strain rates.

[0041] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for predicting failure of composite materials applicable to different strain rates.

[0042] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned methods for predicting failure of composite materials applicable to different strain rates.

[0043] According to the specific embodiments provided in this application, this application has the following technical effects:

[0044] The present application provides a composite material failure prediction method and related device applicable to different strain rates. First, an initial mathematical model for generating a composite material failure envelope is constructed, and then a mechanical property experiment is performed on the composite material under a preset strain rate to obtain the mechanical property parameters of the composite material. The preset strain rate includes the strain rate under static load, the strain rate under quasi-static load and the strain rate under dynamic load. The mechanical property parameters include transverse tensile strength, transverse compressive strength and shear strength. The values ​​of unknown coefficients in the initial mathematical model are determined based on the mechanical property parameters to obtain a mathematical model. The failure envelope of the composite material is generated using the mathematical model, and the safety strength range of the composite material is determined based on the failure envelope. The safety strength range is used to design the structure of the component prepared based on the composite material. The present application constructs an initial mathematical model, and uses the mechanical property parameters to determine the unknown coefficients in the initial mathematical model to obtain a mathematical model. The mathematical model can be used to accurately predict the failure envelope of the composite material, and the mechanical property parameters can be determined under strain rates under different load conditions. Therefore, the failure of the composite material can be accurately predicted under different load conditions, which can solve the strength prediction problem of composite materials under variable load conditions in current theory and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 This is an application environment diagram of a composite material failure prediction method suitable for different strain rates provided in Example 1 of the present application.

[0047] Figure 2 A schematic flow chart of a composite material failure prediction method applicable to different strain rates provided in Example 1 of the present application.

[0048] Figure 3 Schematic diagram of the tensile-compression failure envelope of the unidirectional carbon fiber composite material provided in Example 1 of the present application.

[0049] Figure 4 This is a schematic diagram comparing the failure envelope calculated by this method and the experimental data at three different strain rates provided in Example 1 of the present application.

[0050] Figure 5 Schematic diagram comparing the failure envelopes calculated by the present method and two failure criteria at three different strain rates provided in Example 1 of the present application with experimental data.

[0051] Figure 6 A schematic diagram of the functional modules of a composite material failure prediction device suitable for different strain rates provided in Example 2 of the present application.

[0052] Figure 7 A schematic diagram of the structure of a computer device provided in Example 3 of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] Example 1

[0055] The composite material failure prediction method applicable to different strain rates provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal communicates with the server through the network. The data storage system can store the data that the server needs to process. The data storage system can be set up separately, integrated on the server, or placed on the cloud or other servers. The terminal can send a pending composite material failure prediction request (used to request failure prediction of a specific type of composite material) to the server. After the server receives the pending composite material failure prediction request, for the pending composite material failure prediction request, the server constructs an initial mathematical model for generating a composite material failure envelope; obtains the mechanical property parameters of the composite material; determines the value of the unknown coefficient in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model; generates a failure envelope of the composite material using the mathematical model, and determines the safety strength range of the composite material based on the failure envelope. The safety strength range is used to design the structure of components prepared based on the composite material. The server can feedback the obtained safety strength range of the composite material for the composite material failure prediction request to the terminal.

[0056] In addition, in some embodiments, the composite material failure prediction method suitable for different strain rates can also be implemented independently by a server or a terminal. For example, the terminal can directly process the composite material failure prediction request to be processed, or the server can obtain the composite material failure prediction request to be processed from the data storage system and process the composite material failure prediction request to be processed.

[0057] The terminals may be, but are not limited to, various desktop computers, laptops, smart phones, tablet computers, IoT devices and portable wearable devices. IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server may be implemented as an independent server or a server cluster consisting of multiple servers, or a cloud server.

[0058] In an exemplary embodiment, Figure 2 As shown, a composite material failure prediction method applicable to different strain rates is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The following steps are used to illustrate the server in the example.

[0059] Step S1, constructing an initial mathematical model for generating a failure envelope of a composite material.

[0060] Step S2, obtaining mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under static load, the strain rate under quasi-static load and the strain rate under dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength and shear strength.

[0061] Step S3, determining the values ​​of unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model.

[0062] Step S4, generating a failure envelope of the composite material using the mathematical model, and determining a safe strength range of the composite material based on the failure envelope; the safe strength range is used to design the structure of a component made of the composite material.

[0063] By implementing the above-mentioned steps S1 to S4, for any load condition (static, quasi-static, dynamic), it is only necessary to adjust the strain rate of the composite material under the load condition, and further conduct mechanical property experiments on the composite material to determine the mechanical property parameters. Then, the mathematical model can be determined based on the mechanical property parameters, and the mathematical model can be used to generate the failure envelope of the composite material, further determine the safe strength range of the composite material, and complete the failure prediction of the composite material. At the same time, experiments have shown that the prediction accuracy can be improved.

[0064] Composite materials all exhibit nonlinear behavior and strain rate-dependent properties. Current research focuses on metal alloys or metal composites, and few studies are devoted to studying the strain rate-dependent properties of fiber-reinforced composites. In this embodiment, the composite material may be a carbon fiber composite material CFRP, such as a carbon fiber / epoxy resin composite material AS4 / 3501-6.

[0065] In this embodiment, an initial mathematical model for generating a failure envelope is established according to a tensor-polynomial formula. At this time, the initial mathematical model for generating a failure envelope of a composite material is constructed, specifically including:

[0066] (1) Based on the tensor-polynomial formula, a mathematical formula for generating the failure envelope of a composite material is determined.

[0067] The tensor-polynomial formula is:

[0068] F i σ i +F ij σ i σ j +F ijk σ i σ j σ k+...=1,i,j,k=1,2,…,6 (1)

[0069] In formula (1), F represents coefficient, σ represents stress, and i, j, k represent directions. Since the tensor-polynomial formula is an infinite formula, it is expressed as shown in formula (1). According to the generalization of the criterion in the tensor-polynomial formula, the mathematical formula for generating the failure envelope proposed in this embodiment is obtained according to a special case of the tensor-polynomial formula. In this special case, the stress on the unidirectional layer is σ x , the corresponding coefficient F i =0, F 11 =0, Where m, n, and k are unknown coefficients in the proposed mathematical formula. Therefore, the mathematical formula for generating the failure envelope can be expressed as follows: 2 ,τ 6 ) is described by the equation:

[0070]

[0071] In formula (2), σ 2 is the normal stress perpendicular to the reinforcement direction of the composite material. When the composite material is a fiber-reinforced composite material, the reinforcement direction of the composite material refers to the fiber arrangement direction. At this time, σ 2 is the normal stress perpendicular to the fiber reinforcement layer; τ 6 is the shear stress in the plane of the composite material; m, n, k are all unknown coefficients.

[0072] (2) Considering the influence of strength anisotropy in the transverse direction, the mathematical formula is processed to obtain the initial mathematical model for generating the failure envelope of the composite material.

[0073] In this embodiment, the unknown coefficients m, n, and k are used as numerical values ​​to simplify formula (2). Therefore, these unknown coefficients have no physical meaning. In order to consider the influence of strength anisotropy in the transverse direction, the vertical axis is moved by α. At this time, formula (2) can be replaced by the following expression:

[0074]

[0075] In formula (3), σ 2 is the normal stress perpendicular to the reinforcement direction of the composite material; τ 6 is the shear stress in the plane of the composite material; m, n, k, and α are all unknown coefficients.

[0076] The above formula (3) is the initial mathematical model for generating the failure envelope of the composite material constructed in this embodiment. By deforming the mathematical formula, the mathematical formula can be simplified to obtain a more concise initial mathematical model.

[0077] This embodiment further obtains mechanical property parameters of the composite material. The mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate. The preset strain rate includes the strain rate under static load, the strain rate under quasi-static load and the strain rate under dynamic load. The mechanical property parameters include transverse tensile strength, transverse compressive strength and shear strength, and the transverse direction refers to the direction of normal stress.

[0078] Specifically, this embodiment first determines the strain rate of the composite material, and then conducts a mechanical property experiment on the composite material, specifically a tensile test to obtain the transverse tensile strength. The maximum tensile stress to which the sample is subjected until it breaks is the tensile strength. A compression test is performed to obtain the transverse compressive strength. In the compression test, the compressive stress usually increases with the increase of the compressive strain (i.e., the deformation of the composite material during the compression process) until a maximum value is reached. This maximum value is the compressive strength. A shear test is performed to obtain the shear strength. The shear strength is the ultimate strength of the material when it is sheared, reflecting the ability of the material to resist shear sliding.

[0079] Based on this, this embodiment can determine the mechanical property parameters of the composite material under different load conditions. After obtaining the mechanical property parameters, this embodiment further determines the values ​​of the unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain the mathematical model.

[0080] The calculation formula for m is:

[0081]

[0082] In formula (4), is the transverse tensile strength, i.e. the tensile strength in the transverse direction, is the transverse compressive strength, i.e. the compressive strength in the transverse direction,

[0083] The calculation formula of α is:

[0084]

[0085] To draw the failure envelope of the composite material, the values ​​of the unknown coefficients k and n must also be found. The calculation formulas of k and n are derived according to the boundary condition that the composite material obtains the shear strength at 45 degrees (that is, obtains the maximum shear stress in the composite material layer), that is, the relationship between the two unknown coefficients k and n and the mechanical properties parameters obtained from the mechanical properties experiment is obtained. The specific process is as follows:

[0086] Assuming stress σ x Applied at an angle θ to the reinforcement direction of the composite material, the normal stress σ 2 =σ x sin 2(θ+γ), shear stress τ 6 =-σ x sin(θ+γ)cos(θ+γ), where γ is the shear deformation within the layer. When (θ+γ)=π / 4, the shear stress τ 6 Get the maximum value (i.e. shear strength), located at Figure 3 The vertex A on the failure envelope curve is shown, namely:

[0087]

[0088] In formula (7), Shear strength The corresponding normal stress is Figure 3 shown.

[0089] Based on equation (6) and equation (7), we can get:

[0090]

[0091] Formula (3) has the following expression at vertex A:

[0092]

[0093] By differentiating the implicit function of equation (3), we can obtain:

[0094]

[0095] Since at vertex A τ' 6 =0, so equation (10) has the following expression at vertex A:

[0096]

[0097] The above formula (11) is the calculation formula of k used in this embodiment.

[0098] Based on formula (9) and formula (11), we can get:

[0099]

[0100] The above formula (12) is the calculation formula for n.

[0101] Taking the mechanical property parameters as input, the values ​​of the unknown coefficients can be obtained using equations (4), (5), (11) and (12), that is, the specific values ​​of m, n, α and k. Substituting the specific values ​​of m, n, α and k into equation (3), the mathematical model for generating the failure envelope can be obtained. At this time, the mathematical model is an expression that is only related to the transverse tensile strength and transverse compressive strength in the transverse direction of the composite material and the shear strength in the layer plane.

[0102] After obtaining the mathematical model, this embodiment further uses the mathematical model to generate a failure envelope of the composite material, and determines a safe strength range of the composite material based on the failure envelope. The safe strength range is used to design the structure of a component made of the composite material.

[0103] Among them, the failure envelope of the composite material is generated by using a mathematical model, and the safety strength range of the composite material is determined based on the failure envelope, specifically including:

[0104] (1) A plurality of normal stress values ​​are randomly selected within a preset value range, wherein the minimum value of the preset value range is the transverse compressive strength, and the maximum value of the preset value range is the transverse tensile strength.

[0105] (2) For each value of normal stress, the value of normal stress is used as input, and the value of shear stress is determined using a mathematical model, and the value of normal stress and the value of shear stress are combined into one data point.

[0106] (3) With normal stress as the x-axis and shear stress as the y-axis, all data points are connected to obtain the failure envelope of the composite material.

[0107] The failure envelope of a composite material is Figure 3 shown.

[0108] (4) The area formed by the failure envelope, the x-axis and the y-axis is taken as the safe area, and the values ​​of the normal stress and the shear stress within the safe area constitute the safe strength range of the composite material.

[0109] This embodiment provides a failure theory mathematical model that is adaptable to different strain rates and is used to analyze the behavior of composite materials under tension, compression, and shear in the layer plane transverse to the reinforcement direction of the composite material. The strain rates under various loading conditions, including quasi-static, static, and dynamic loading conditions, are taken into account. The proposed mathematical model provides a basis for predicting the fracture and progressive damage of composite materials under various loading conditions, and improves the accuracy of the prediction. The method can be further adjusted and expanded to explore other aspects of material behavior and structural performance, providing valuable insights for design and analysis.

[0110] The method of this embodiment has the following advantages: ① It is only necessary to obtain the transverse tensile strength and transverse compressive strength in the transverse direction of the composite material and the shear strength in the layer plane through mechanical property experiments to generate a mathematical model, and the failure envelope of the composite material can be predicted using the mathematical model; ② The mathematical model is applicable under different strain rates; ③ The mathematical model is concise and clear as a whole.

[0111] The method proposed in this embodiment is further verified below.

[0112] During 2003-2013, several worldwide failure exercises were conducted to test the capabilities of various current methods for predicting the strength of composite sheets and laminates. Some workers in the field of composite failure theory were invited to compare their theories with experimental data provided by the organizers. This example obtained accurate experimental data from them, as shown in Tables 1 and 2.

[0113] Table 1 Experimental data of carbon fiber / epoxy resin composite material AS4 / 3501-6

[0114]

[0115] It should be noted that the pure shear strength in Table 1 refers to the maximum shear stress that the composite material can withstand when subjected to shear only.

[0116] Table 2 Characteristic data of carbon fiber / epoxy resin composite AS4 / 3501-6 at different strain rates

[0117]

[0118] Based on the characteristic data provided in Table 2, the coefficients m, n, α and k at various strain rates can be determined, see Table 3.

[0119] Table 3 Values ​​of coefficients m, n, α and k

[0120]

[0121] Figure 4 In order to compare the failure envelope calculated by the method proposed in this embodiment with the experimental data (including the experimental data in Table 1) at different strain rates, Figure 4 The three curves in are the failure envelopes calculated using the method proposed in this embodiment. Figure 4 The three data points in are experimental data. The results show that the calculated results are highly consistent with the experimental data, indicating the reliability and accuracy of the method proposed in this embodiment.

[0122] Figure 5 In order to utilize the method proposed in this embodiment (i.e. Figure 5 The failure envelopes calculated by the present method, the NU-Daniel failure criterion, and the Hashin failure criterion are compared with the experimental data. Figure 5In the figure, there are three failure envelopes calculated by the method proposed in this embodiment, the failure envelopes calculated by the NU-Daniel failure criterion, and the failure envelopes calculated by the Hashin failure criterion, which are the failure envelopes under dynamic conditions, the failure envelopes under static conditions, and the failure envelopes under quasi-static conditions from top to bottom. Obviously, the method proposed in this embodiment is more accurate than the Hashin failure criterion.

[0123] In order to compare the accuracy of the NU-Daniel failure criterion and the method proposed in this example, the determination coefficient (R 2 Table 4 provides the determination coefficients of the NU-Daniel failure criterion and the method proposed in this embodiment at different strain rates, which indicates that the method proposed in this embodiment has higher accuracy in predicting the mechanical behavior of the composite material at different strain rates.

[0124] Table 4 Determination coefficient values ​​of failure envelope.

[0125]

[0126] Existing literature indicates that the NU-Daniel failure criterion more accurately describes the failure envelopes at three different strain rates than traditional failure criteria (including maximum stress, maximum strain, Tsai-Hill, Tsai-Wu, Sun, etc.), and the method proposed in this embodiment is more accurate than the NU-Daniel failure criterion. It is worth noting that compared with other failure criteria, the failure envelopes generated by the method proposed in this embodiment have higher consistency with the experimental data at various strain rates.

[0127] The present application also provides an application scenario, which applies the above-mentioned composite material failure prediction method applicable to different strain rates. Specifically, the composite material failure prediction method applicable to different strain rates provided in this embodiment can be applied in the composite material structure design scenario. The composite material structure design scenario includes a failure prediction link and a structural design link. The failure prediction link is used to generate a mathematical model, further draw the failure envelope of the composite material, and obtain the safe strength range of the composite material. The structural design link is used to perform structural design based on the safe strength range of the composite material. The composite material failure prediction method applicable to different strain rates provided in this embodiment belongs to the failure prediction link.

[0128] Example 2

[0129] Based on the same inventive concept, the embodiment of the present application also provides a composite material failure prediction device applicable to different strain rates for implementing the composite material failure prediction method applicable to different strain rates involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of composite material failure prediction devices applicable to different strain rates provided below can refer to the limitations of composite material failure prediction methods applicable to different strain rates above, and will not be repeated here.

[0130] In an exemplary embodiment, Figure 6 As shown, a composite material failure prediction device applicable to different strain rates is provided, and the composite material failure prediction device applicable to different strain rates comprises:

[0131] The model building module M1 is used to build an initial mathematical model for generating the failure envelope of the composite material.

[0132] The parameter acquisition module M2 is used to obtain the mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under static load, the strain rate under quasi-static load and the strain rate under dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength and shear strength.

[0133] The model generation module M3 is used to determine the values ​​of the unknown coefficients in the initial mathematical model based on the mechanical performance parameters to obtain the mathematical model.

[0134] The failure prediction module M4 is used to generate a failure envelope of the composite material using the mathematical model, and determine a safe strength range of the composite material based on the failure envelope; the safe strength range is used to design the structure of a component made of the composite material.

[0135] Example 3

[0136] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 7As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a composite material failure prediction method suitable for different strain rates is implemented.

[0137] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0138] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the composite material failure prediction method applicable to different strain rates in Example 1 is implemented.

[0139] Example 4

[0140] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which, when executed by a processor, implements the composite material failure prediction method applicable to different strain rates in Example 1.

[0141] Example 5

[0142] In an exemplary embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the composite material failure prediction method applicable to different strain rates in Embodiment 1.

[0143] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0144] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A composite material failure prediction method applicable to different strain rates, characterized in that: The composite material failure prediction method applicable to different strain rates includes: Constructing an initial mathematical model for generating composite material failure envelopes; Obtaining mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under a static load, the strain rate under a quasi-static load, and the strain rate under a dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength, and shear strength; Determining the values ​​of unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model; The mathematical model is used to generate a failure envelope of the composite material, and a safe strength range of the composite material is determined based on the failure envelope; the safe strength range is used to design the structure of a component prepared based on the composite material.

2. The composite material failure prediction method applicable to different strain rates according to claim 1, characterized in that: Construct an initial mathematical model for generating the failure envelope of composite materials, including: Determine a mathematical formula for generating a composite material failure envelope based on a tensor-polynomial formula; Taking into account the influence of strength anisotropy in the transverse direction, the mathematical formula is processed to obtain an initial mathematical model for generating a failure envelope of the composite material.

3. The composite material failure prediction method applicable to different strain rates according to claim 2, characterized in that: The mathematical formula is: Among them, σ2 is the normal stress perpendicular to the reinforcement direction of the composite material; τ6 is the shear stress in the plane of the composite material; m, n, and k are all unknown coefficients.

4. The composite material failure prediction method applicable to different strain rates according to claim 2, characterized in that: The initial mathematical model is: Among them, σ2 is the normal stress perpendicular to the reinforcement direction of the composite material; τ6 is the shear stress in the plane of the composite material; m, n, k, and α are all unknown coefficients.

5. The composite material failure prediction method applicable to different strain rates according to claim 4, characterized in that: The calculation formula for m is: in, is the transverse tensile strength; is the transverse compressive strength; The calculation formula of α is: The calculation formula for k is: in, is the normal stress corresponding to the shear strength; is the shear strength; The calculation formula for n is:

6. The composite material failure prediction method applicable to different strain rates according to claim 4, characterized in that: The failure envelope of the composite material is generated by using the mathematical model, and the safety strength range of the composite material is determined based on the failure envelope, specifically including: A plurality of normal stress values ​​are randomly selected within a preset value range; the minimum value of the preset value range is the transverse compression strength, and the maximum value of the preset value range is the transverse tensile strength; For each value of normal stress, the value of normal stress is used as input, the value of shear stress is determined using the mathematical model, and the value of normal stress and the value of shear stress are combined into one data point; Taking the normal stress as the x-axis and the shear stress as the y-axis, all the data points are connected to obtain the failure envelope of the composite material; The area formed by the failure envelope, the x-axis and the y-axis is taken as a safe area, and the values ​​of the normal stress and the shear stress within the safe area constitute the safe strength range of the composite material.

7. A composite material failure prediction device suitable for different strain rates, characterized in that: The composite material failure prediction device applicable to different strain rates comprises: a model building module for building an initial mathematical model for generating a failure envelope of a composite material; A parameter acquisition module, used to acquire mechanical property parameters of the composite material; the mechanical property parameters are parameters obtained by conducting a mechanical property experiment on the composite material under a preset strain rate, the preset strain rate includes the strain rate under a static load, the strain rate under a quasi-static load, and the strain rate under a dynamic load, and the mechanical property parameters include transverse tensile strength, transverse compressive strength, and shear strength; A model generation module, used to determine the values ​​of unknown coefficients in the initial mathematical model based on the mechanical property parameters to obtain a mathematical model; A failure prediction module is used to generate a failure envelope of the composite material using the mathematical model, and determine a safe strength range of the composite material based on the failure envelope; the safe strength range is used to design the structure of a component prepared based on the composite material.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the composite material failure prediction method applicable to different strain rates as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the composite material failure prediction method applicable to different strain rates described in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the composite material failure prediction method applicable to different strain rates described in any one of claims 1 to 6 is implemented.

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