Extrusion damage prediction method, device, equipment, medium and program product

Abstract

The invention discloses an extrusion damage prediction method, device and equipment, a medium and a program product. The method comprises the following steps: determining a composite material hole extrusion finite element model; according to the material performance of the composite material laminated plate in the composite material hole extrusion finite element model, the material stress of a material unit in the extrusion process is determined; determining a failure material unit according to the material stress of the material unit and a preset failure criterion, and performing material performance reduction processing on the failure material unit based on a failure mode; and if the extrusion process is finished, determining a stress distribution animation of the hole wall area according to the material stress of the material unit, and displaying extrusion damage information of the composite material hole according to the stress distribution animation. According to the embodiment of the invention, the problems that the damage of the composite material hole wall cannot be directly observed, a lot of time needs to be consumed, and the hole wall damage determination efficiency is influenced are solved, and the damage state of the composite material hole wall can be rapidly and effectively determined.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of computer, and in particular, to a hole extrusion damage prediction method, device, equipment, medium and program product. BACKGROUND

[0002] Hole extrusion technology has been widely used in the strengthening of metal materials, significantly improving the fatigue life of the workpiece with holes, and has been extensively studied and widely used in the field of aviation manufacturing.

[0003] During the composite extrusion process, the metal bushing will cause different degrees of damage to the composite hole wall due to the extrusion effect, which will cause obvious damage to the performance of the composite material and reduce the service performance of the composite material. At the same time, the damage of the composite hole wall cannot be directly observed, and needs to be destroyed and then subjected to complex composite damage test observation and statistical operation, which requires a lot of time and affects the efficiency of determining the damage of the hole wall. SUMMARY

[0004] The hole extrusion damage prediction method, device, equipment, medium and program product provided by the embodiments of the present application can quickly and effectively predict the hole wall damage in the composite hole extrusion process.

[0005] According to an aspect of the present application, a hole extrusion damage prediction method is provided, comprising:

[0006] determining a composite hole extrusion finite element model, wherein the composite hole extrusion finite element model comprises a geometric model of a composite laminate, and the geometric model comprises material units of a hole wall region;

[0007] determining material stress of the material units in the extrusion process according to material properties of the composite laminate in the composite hole extrusion finite element model;

[0008] determining a failed material unit according to the material stress of the material units and a preset failure criterion, and performing material property reduction processing on the failed material unit based on a failure mode;

[0009] if the extrusion process is completed, determining a stress distribution animation of the hole wall region according to the material stress of the material units, and displaying composite hole extrusion damage information according to the stress distribution animation.

[0010] According to another aspect of the present application, a hole extrusion damage prediction device is provided, comprising:

[0011] a model determination module configured to determine a composite hole extrusion finite element model, wherein the composite hole extrusion finite element model comprises a geometric model of a composite laminate, and the geometric model comprises material units of a hole wall region;

[0012] a stress determining module configured to determine material stress of the material unit in the extrusion process according to material properties of the composite laminate in the composite hole extrusion finite element model;

[0013] a failure judging module configured to determine a failed material unit according to the material stress of the material unit and a preset failure criterion, and perform material property reduction processing on the failed material unit based on a failure mode;

[0014] an animation generating module configured to determine a stress distribution animation of the hole wall region according to the material stress of the material unit if the extrusion process ends, and display composite hole extrusion damage information according to the stress distribution animation.

[0015] According to another aspect of the present application, an electronic device is provided, which comprises:

[0016] at least one processor;

[0017] and a memory connected in communication with the at least one processor;

[0018] wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the extrusion damage prediction method according to any of the embodiments of the present application.

[0019] According to another aspect of the present application, a computer readable storage medium is provided, which stores computer instructions for enabling a processor to implement the extrusion damage prediction method according to any of the embodiments of the present application when executed by the processor.

[0020] According to another aspect of the present application, a computer program product is provided, which comprises a computer program for implementing the extrusion damage prediction method according to any of the embodiments of the present application when executed by a processor.

[0021] The technical scheme of the embodiment of the application comprises the following steps: determining a composite material hole extrusion finite element model; determining material stress of a material unit in an extrusion process according to material performance of a composite material laminate in the composite material hole extrusion finite element model; determining a failed material unit according to the material stress of the material unit and a preset failure criterion; performing material performance reduction processing on the failed material unit based on a failure mode; if the extrusion process ends, determining a stress distribution animation of a hole wall region according to the material stress of the material unit, and displaying composite material hole extrusion damage information according to the stress distribution animation, thereby solving the problem that damage of a composite material hole wall cannot be directly observed and a large amount of time is consumed to affect hole wall damage determination efficiency, and damage of the composite material hole wall can be quickly and effectively determined.

[0022] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0024] Figure 1 A flowchart of an extrusion damage prediction method is provided for the embodiment of the application.

[0025] Figure 2 A schematic diagram of a composite material hole extrusion finite element model is provided for the embodiment of the application.

[0026] Figure 3 A flowchart of an extrusion process composite material hole wall damage prediction is provided for the embodiment of the application.

[0027] Figure 4 A stress distribution simulation nephogram of a bushing after hole extrusion is provided for the embodiment of the application.

[0028] Figure 5 A flowchart of another extrusion damage prediction method is provided for the embodiment of the application.

[0029] Figure 6 A stress distribution nephogram around a 0-degree layer carbon fiber composite material hole wall is provided for the embodiment of the application.

[0030] Figure 7 A composite material hole wall stress distribution nephogram after hole extrusion is provided for the embodiment of the application.

[0031] Figure 8 A structural schematic diagram of an extrusion damage prediction device provided for an embodiment of the present application is shown in the figure.

[0032] Figure 9 A structural schematic diagram of an electronic device provided for an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0033] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application.

[0034] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to the process, method, product or device.

[0035] Figure 1 A flowchart of an extrusion damage prediction method provided for an embodiment of the present application is shown in the figure. The present embodiment can be applicable to a hole extrusion strengthening scenario, for example, to damage prediction of a composite material during an extrusion process. The method can be executed by an extrusion damage prediction device, which can be realized in the form of hardware and / or software, and can be configured in an electronic device. For example, the electronic device includes a server and the like. As shown in the figure, the method includes: Figure 1

[0036] S110, determining a composite material hole extrusion finite element model, wherein the composite material hole extrusion finite element model includes a geometric model of a composite material laminate, and the geometric model includes material units of a hole wall region.

[0037] ​The composite hole can include a fitting hole of a composite part, etc. Application of the composite large-scale integral manufacturing technology greatly reduces the number of aircraft parts, but a large number of design separation surfaces and process separation surfaces still exist between the composite parts due to various requirements of design, process, maintenance and transportation. Mechanical connection is the main form of connection of the composite parts, which destroys the integrity of the integral structure, and introduces significant stress concentration phenomenon, and each fitting hole is a potential failure source, and the mechanical connection part is also a weak link of the integral structure.

[0038] With increasing emphasis on the fatigue resistance manufacturing technology of the composite structure fitting hole, research on the cold extrusion strengthening of the composite connection hole is increasing at home and abroad. Studies have shown that for the composite fitting hole, using a metal bushing in combination with the hole extrusion strengthening process can improve the hole opening compression strength and hole edge wear resistance, prevent damage to the hole by the connecting part, and effectively improve the fatigue life of the structure.

[0039] The composite hole extrusion finite element model is a model that uses finite element analysis method to simulate and predict the mechanical behavior, stress and strain distribution and damage evolution of the composite material during the hole extrusion process. Through the finite element analysis software, the composite material laminated plate model, the mandrel model and the bushing model are combined to simulate the composite material hole extrusion process.

[0040] Exemplarily, according to the layer direction and layer thickness of the composite laminated plate, and the tensile and compressive elastic modulus, shear elastic modulus and Poisson's ratio corresponding to the layer direction, an anisotropic constitutive model of the composite laminated plate is determined. According to the size, layer thickness, geometric parameters of the opening of the composite laminated plate, the geometric model and model of the anisotropic constitutive model, the mandrel and the bushing, the geometric model of the composite laminated plate, the mandrel and the bushing is determined. Based on the geometric model of the composite laminated plate, the mandrel and the bushing, the preset assembly parameters and the boundary conditions of the extrusion process, a composite hole extrusion finite element model is determined. The preset assembly parameters include the extrusion displacement increment corresponding to each time step in the extrusion process.

[0041] In some embodiments, the composite laminated plate includes a carbon fiber reinforced composite laminated plate, etc. The layer direction and layer thickness of each layer in the carbon fiber reinforced composite laminated plate are obtained. The tensile and compressive elastic modulus, shear elastic modulus and Poisson's ratio of each layer direction are measured. The orthotropic material stiffness matrix and flexibility matrix are established and solved by the principle of composite mechanics. The anisotropic constitutive model of the carbon fiber reinforced composite laminated plate is determined according to the stiffness matrix and flexibility matrix.

[0042] In some embodiments, the size, anisotropic constitutive model, ply thickness, and geometric parameters of the opening of the composite laminate are obtained. The geometric parameters and model of the mandrel and the bushing are obtained. The size, anisotropic constitutive model, ply thickness, and geometric parameters of the opening of the composite laminate, and the geometric parameters and model of the mandrel and the bushing are input into a finite element analysis software. The material of the mandrel and the bushing is selected in the finite element analysis software, and the mechanical property parameters of the mandrel and the bushing are determined according to the selected material. A geometric model of the composite laminate with the opening, the mandrel, and the bushing is established in the finite element analysis software, and is assembled based on preset assembly parameters. Then, boundary conditions of the extrusion process are input into the finite element analysis software based on expected conditions of the extrusion process, so as to establish a composite material hole extrusion finite element model.

[0043] Figure 2 A schematic diagram of the composite material hole extrusion finite element model provided by the embodiments of the present application is shown in FIG. 2. As shown in FIG. 2, the composite material hole extrusion finite element model includes a composite laminate 200, a mandrel 210, and a bushing (not shown), and the composite laminate 200 has an opening. The mandrel 210 is inserted into the opening. Figure 2

[0044] S120, according to the material performance of the composite laminate in the composite material hole extrusion finite element model, determining the material stress of the material unit in the extrusion process.

[0045] For the composite laminate, the material performance can be characterized by the constitutive relation of the composite laminate. The constitutive relation of the composite laminate includes a stiffness matrix and / or a flexibility matrix. The material stress of the current layer can be solved by the stiffness matrix and / or the flexibility matrix of any layer in the composite laminate.

[0046] Exemplarily, according to the extrusion displacement increment corresponding to the current time step and the anisotropic constitutive model, the strain increment of the current time step is determined, wherein the anisotropic constitutive model includes the stiffness matrix and the flexibility matrix of the material unit. According to the material strain of the previous time step of the material unit and the strain increment of the current time step, the material strain of the current time step is determined. According to the material strain corresponding to each time step in the extrusion process, the material stress corresponding to each time step is determined.

[0047] The time step refers to a time interval. The time step is used to control the accuracy and stability of the simulation of the hole extrusion process. If the time step is too large, numerical instability may occur, and if the time step is too small, the calculation cost will increase. Therefore, setting a reasonable time step can balance the accuracy of the simulation results of the hole extrusion and the calculation efficiency.

[0048] ​The extrusion displacement increment represents the displacement increase value of the mandrel at a single time step. The strain increment is the strain change amount corresponding to the extrusion displacement increment during the extrusion process. For example, at the nth time step, the strain increment can represent the strain change amount generated by the extrusion displacement increment from the (n-1)th time step to the nth time step.

[0049] In the composite laminate, the material stress of each layer can be calculated based on the material strain of the current layer and the compliance coefficients or stiffness coefficients of the corresponding layer in the anisotropic constitutive model. The stiffness matrix includes a plurality of stiffness coefficients. The compliance matrix includes a plurality of compliance coefficients.

[0050] For example, in the finite element analysis software, the stress state of the area near the hole wall of the composite laminate is analyzed according to the boundary conditions and the anisotropic constitutive model in combination with the finite element analysis method, and the stress state of each layer of the composite laminate at each time step is output.

[0051] S130, determining a failed material unit according to the material stress of the material unit and a preset failure criterion, and performing material performance reduction processing on the failed material unit based on a failure mode.

[0052] The preset failure criterion is used to determine whether the material unit is failed. For example, the preset failure criterion includes a plurality of failure criteria. For example, the failure criteria include fiber tensile failure criterion, fiber compression failure criterion, matrix tensile failure criterion, matrix compression failure criterion, fiber-matrix shear failure criterion, tensile delamination failure criterion, and compression delamination failure criterion. Each failure criterion includes preset failure criterion value calculation logic. The failure mode is determined according to the failure criterion, and different failure modes are associated with different failure criterion value calculation logics. The failure criterion value under the corresponding failure mode can be calculated based on the material stress of the material unit and the failure criterion calculation logic corresponding to each failure mode. If the failure criterion value exceeds 1, it is determined that the failure mode of the material unit is the corresponding failure mode. Optionally, the failure mode includes at least one of fiber tensile failure, fiber compression failure, matrix tensile failure, matrix compression failure, fiber-matrix shear failure, tensile delamination failure, and compression delamination failure.

[0053] The failed material unit refers to a material unit that has failed. The material performance reduction processing refers to a reduction processing of material performance (e.g., stiffness and strength) of the failed material unit, so as to more accurately simulate the mechanical behavior of the material after damage. Optionally, the material performance reduction processing includes stiffness degradation processing and the like. For example, the stiffness of the failed material unit can be reduced according to a performance degradation model. In some embodiments, the performance degradation model can be a mathematical model for realizing stiffness reduction based on a failure mode. The performance degradation model includes a logical relationship of a degradation factor, tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio. Optionally, the performance degradation model defines the degradation factor under different failure modes. The tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio of the failed material unit are substituted into the performance degradation model, and the degradation factor corresponding to the failure model is combined, so as to calculate the tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio after stiffness degradation. Further, according to the tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio after stiffness degradation, a new stiffness matrix and flexibility matrix are calculated, so as to realize the material performance reduction processing of the failed material unit.

[0054] In S140, if the extrusion process ends, a stress distribution animation of the hole wall region is determined according to the material stress of the material unit, and the composite material hole extrusion damage information is displayed according to the stress distribution animation.

[0055] For example, if the extrusion process ends, the material stress corresponding to each time step of the material unit is obtained. The stress distribution graph of the hole wall region is generated according to the material stress corresponding to each time step, and the stress distribution graphs of the time steps are spliced in sequence to obtain the stress distribution animation of the hole wall region.

[0056] Optionally, for each time step, different colors can be used to represent the size of the material stress of each material unit, and then the stress distribution graph near the hole wall region of the composite material laminate is drawn. The stress distribution graphs corresponding to each time step are spliced in sequence to obtain the stress distribution animation near the hole wall region, so as to dynamically display the stress distribution state of the hole wall region.

[0057] If the extrusion process has not ended, a next time step is obtained by updating the time step according to a preset time. Then, the material stress of the material unit corresponding to the next time step is determined, the failed material unit is determined according to the material stress of the material unit corresponding to the next time step and a preset failure criterion, and the material performance reduction processing of the failed material unit is performed based on the failure mode. After each failure determination and material performance reduction, the material strain and material stress calculation step of the next time step is entered, and the failure determination and material performance reduction are performed again until the extrusion process ends.

[0058] The technical scheme of the embodiment of the present application can respectively perform extrusion damage prediction on different types of composite material laminates, and can quickly and accurately obtain the hole wall damage of different composite materials under the hole extrusion process through the prediction and analysis of the composite material hole wall damage in the extrusion process.

[0059] The technical scheme of the embodiment of the present application determines the composite material hole extrusion finite element model, determines the material stress of the material unit in the extrusion process according to the material performance of the composite material laminates in the composite material hole extrusion finite element model, determines the failure material unit according to the material stress of the material unit and the preset failure criterion, performs material performance reduction processing on the failure material unit based on the failure mode, and if the extrusion process is ended, determines the stress distribution animation of the hole wall region according to the material stress of the material unit, and displays the composite material hole extrusion damage information according to the stress distribution animation, thereby solving the problem that the damage of the composite material hole wall cannot be directly observed and a large amount of time is consumed to affect the determination efficiency of the hole wall damage, and the damage of the composite material hole wall can be quickly and effectively determined.

[0060] In some specific embodiments, a specific prediction method of the composite material hole wall damage in the extrusion process is further provided. Figure 3 An extrusion process composite material hole wall damage prediction flowchart is provided for the embodiment of the present application. Figure 3 As shown in the figure, the method comprises the following steps.

[0061] S310, a composite material hole extrusion finite element model is constructed.

[0062] S320, the state variable value of the initial time step is set to 0.

[0063] The state variable is used to store information related to the material state. For example, the state variable includes damage or failure, etc. When the value of the state variable is 0, it indicates that the material unit has not been damaged or failed. When the value of the state variable is 1, it indicates that the material unit has been damaged or failed, and the stiffness parameter of the material unit has been reduced according to the performance degradation model.

[0064] S330, the extrusion displacement is increased.

[0065] The extrusion displacement is increased with the extrusion process, and each extrusion displacement increment corresponds to a strain increment.

[0066] S340, the material strain of the material unit at the current time step is calculated according to the extrusion displacement increment, and the material stress is calculated according to the material strain.

[0067] It should be noted that if the material stress and the material strain do not converge, the process is ended.

[0068] S350. Determine whether the material unit is failed based on the material stress. If so, execute S360; otherwise, execute S380.

[0069] S360. Perform stiffness return processing on the failed material unit.

[0070] S370. Update the state variable value to 1.

[0071] S380: Determine whether the extrusion process is completed. If so, execute S390; otherwise, execute S3100.

[0072] S390. Output stress distribution animation of the hole wall area.

[0073] S3100 , determine the next time step by increasing the current time step by Δt, and return to execute S340 .

[0074] Figure 4 This is a simulation cloud diagram of bushing stress distribution after hole extrusion provided by an embodiment of the present invention. Figure 4 As shown, different areas of the bushing have different colors, and different colors represent different amounts of stress.

[0075] Figure 5 The present invention provides a flowchart of another method for predicting crush damage. Based on the above embodiments, the method for predicting crush damage is specifically defined. Figure 5 As shown, the method includes:

[0076] S510: Determine a composite material hole extrusion finite element model, wherein the composite material hole extrusion finite element model includes a geometric model of the composite material laminate, and the geometric model includes material units in the hole wall area.

[0077] Exemplarily, the anisotropic constitutive model of the composite laminate is determined based on the ply direction, ply thickness, and the tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio corresponding to the ply direction. The geometric model of the composite laminate, mandrel, and bushing is determined based on the dimensions of the composite laminate, ply thickness, geometric parameters of the opening, the anisotropic constitutive model, and geometric parameters and models of the mandrel and bushing. The finite element model of the composite hole extrusion is determined based on the geometric models of the composite laminate, mandrel, and bushing, preset assembly parameters, and boundary conditions of the extrusion process.

[0078] In some embodiments, the stiffness matrix and the flexibility matrix are determined based on the ply direction, ply thickness, and the tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio corresponding to the ply direction of the composite laminate.

[0079] Composite laminates belong to orthotropic materials. For orthotropic materials, any point has three mutually perpendicular elastic symmetry planes. Therefore, by strain energy density analysis, it can be proved that the independent elastic constants in the stiffness matrix and the compliance matrix will be reduced to 9, and the compliance matrix of orthotropic materials can be expressed as:

[0080]

[0081] where S 11 , S 12 , S 13 , S 21 , S 22 , S 23 , S 31 , S 32 , S 33 , S 44 , S 55 and S 66 represent the compliance coefficients.

[0082] In engineering practical applications, the elastic constants (such as tensile and compressive elastic modulus, shear elastic modulus and Poisson's ratio) are usually used to represent the elastic properties of anisotropic materials, so the compliance matrix of orthotropic materials can be expressed as:

[0083]

[0084] where E i is the tensile and compressive elastic modulus of the principal direction, i = 1, 2, 3; G 23 , G 31 and G 12 are the shear elastic modulus of the three plane directions; v 21 , v 31 , v 12 , v 32 , v 13 and v 23 are Poisson's ratios.

[0085] The stiffness matrix C of orthotropic materials can be solved according to the compliance matrix, and the components of the stiffness matrix are:

[0086]

[0087] where a = 1-v 12 v 21 -v 23 v 32 -v 13 v 31 -2v 21 v 32 v 13 .

[0088] According to the stiffness matrix and the compliance matrix, the anisotropic constitutive model of the composite laminated plate is determined.

[0089] Optionally, according to the ply direction, the ply thickness of the composite laminated plate, and the tensile and compressive elastic modulus, the shear elastic modulus and the Poisson's ratio corresponding to the ply direction, the anisotropic constitutive model of the composite laminated plate is determined, comprising:

[0090] According to the ply direction, the ply thickness of the composite laminated plate, and the tensile and compressive elastic modulus, the shear elastic modulus and the Poisson's ratio corresponding to the ply direction, the stiffness matrix and the compliance matrix are determined.

[0091] If the included angle between the principal axis direction of the ply of at least one composite layer in the composite laminated plate and the principal axis direction of the target component corresponding to the composite laminated plate is not zero, the coordinate conversion matrix is determined according to the included angle.

[0092] Since the ply angles of each sublayer of the composite laminated plate are different, the analysis and design of the composite material are generally carried out in the global coordinate system, and the principal axis directions of each ply are usually different from the principal axis direction of the global coordinate system, so it is necessary to perform coordinate conversion on each ply. Assuming that there is an included angle α between the fiber ply angle of any sublayer and the global coordinate system, the coordinate conversion matrix T can be represented as:

[0093]

[0094] Wherein, m = cosα, n = sinα.

[0095] According to the coordinate conversion matrix, the stiffness matrix and the compliance matrix, the anisotropic constitutive model of the composite laminated plate is determined.

[0096] Thus, the stiffness matrix and the compliance matrix of any sublayer in the global coordinate system can be obtained

[0097] The above formula describes the anisotropic constitutive model of the composite laminated plate, and can solve the stress and strain state of any sublayer.

[0098]

[0099] S520, according to the extrusion displacement increment corresponding to the current time step and the anisotropic constitutive model, the strain increment of the current time step is determined.

[0100] S530, according to the material strain of the material unit in the previous time step and the strain increment of the current time step, the material strain of the current time step is determined.

[0101] ​S540, determine the material stress corresponding to each time step according to the material strain corresponding to each time step in the extrusion process.

[0102] Illustratively, the material stress of the material unit corresponding to each time step is determined according to the material strain corresponding to each time step and the stiffness matrix.

[0103] For example, the product of the material strain ε corresponding to the current time step and the stiffness matrix C is taken as the material stress σ = C·ε corresponding to the current time step.

[0104] S550, determine the failure state and failure mode of the material unit corresponding to the current time step according to the failure criterion corresponding to the preset failure criterion and the material stress corresponding to the current time step, wherein the failure state represents whether the material unit fails.

[0105] For example, the material stress corresponding to the current time step is substituted into the failure criterion corresponding to the preset failure criterion to determine whether the material unit fails in each failure mode. The material unit that fails is referred to as a failed material unit. In addition, the failure mode that fails is determined.

[0106] S560, if the material unit is a failed material unit, determine the degradation factor of the failed material unit according to the failure mode, update the stiffness matrix and compliance matrix of the failed material unit according to the degradation factor, and update the anisotropic constitutive model corresponding to the next time step.

[0107] If the material unit is a failed material unit, the stiffness of the failed material unit can be reduced according to the performance degradation model. The product of the stiffness matrix after the stiffness parameter reduction and the material strain corresponding to the current time step is used to update the material stress corresponding to the current time step.

[0108] Optionally, the failure is determined based on the progressive damage model, and the material performance of the failed material unit is reduced according to the failure mode. The steps S520-S550 are repeated until the extrusion process ends, the core rod is separated from the liner, and the stress and strain no longer change, and the cycle is stopped.

[0109] The progressive damage model is an analysis method based on the composite continuum damage constitutive model of mechanics, and the main process is to obtain the stress distribution state from the composite stress analysis model, to determine the failure state of the material unit according to the preset failure criterion, to reduce the material performance of the failed material unit, and to realize the analysis and prediction of the failure process of the composite material. For example, the preset failure criterion can include 3D Hashin failure criterion.

[0110] S570, if the material unit is a non-failed material unit, the anisotropic constitutive model corresponding to the current time step is taken as the anisotropic constitutive model corresponding to the next time step.

[0111] If the material unit is a non-failed material unit, the material stress corresponding to the current time step is not updated, and the anisotropic constitutive model corresponding to the current time step is taken as the anisotropic constitutive model corresponding to the next time step.

[0112] S580, if the extrusion process is finished, the stress distribution animation of the hole wall region is determined according to the material stress of the material unit, and the composite material hole extrusion damage information is displayed according to the stress distribution animation.

[0113] If the extrusion process is finished, the material stress corresponding to each time step of the composite material laminate during the hole extrusion process is obtained to determine the stress distribution state of the hole wall, and then the stress distribution nephogram of the hole wall region is determined according to the stress distribution state of the hole wall, and the hole wall damage prediction result is characterized by the stress distribution nephogram. The stress distribution nephogram of the hole wall region includes the stress distribution nephogram of each layer of the composite material laminate, and also includes the stress distribution nephogram of the whole hole. Figure 6 A stress distribution nephogram around a 0-degree layer carbon fiber composite material hole wall is provided for an embodiment of the present application. Figure 7 A stress distribution nephogram of a hole wall after composite material hole extrusion is provided for an embodiment of the present application.

[0114] The stress distribution nephograms are spliced in the order of time steps to obtain the stress distribution animation of the hole wall region.

[0115] Optionally, a new composite material hole extrusion finite element model can also be established by switching the geometric parameters and models of the mandrel and the liner in the finite element analysis software. Then, the hole wall damage prediction result under the current parameters is predicted in the above manner. Furthermore, by constructing a plurality of composite material hole extrusion finite element models under a plurality of geometric parameters and models of the mandrel and the liner, the optimal mandrel and liner parameters can be selected, and the strengthening effect of the composite material hole extrusion process can be quickly and effectively improved, and the fatigue life and service performance of the composite material component connection part can be increased.

[0116] In the embodiments of the present disclosure, the damage state of the material near the hole wall region during the composite material hole extrusion process is predicted, and part of the delamination defects that cannot be directly observed can be predicted. At the same time, the complex composite material laminate damage test observation and statistics link can be omitted, the damage prediction time of the material near the hole wall region is reduced, and the prediction efficiency is improved.

[0117] Figure 8A structural schematic diagram of an extrusion damage prediction device provided for an embodiment of the present application. The extrusion damage prediction device can be realized in the form of hardware and / or software, and can be configured in an electronic device. For example, the electronic device includes a server and the like.

[0118] As shown in the figure, the device includes a model determination module 810, a stress determination module 820, a failure judgment module 830, and an animation generation module 840. Figure 8

[0119] The model determination module 810 is configured to determine a composite material hole extrusion finite element model, wherein the composite material hole extrusion finite element model includes a geometric model of a composite material laminate, and the geometric model includes material units of a hole wall region.

[0120] The stress determination module 820 is configured to determine material stress of the material units in the extrusion process according to material performance of the composite material laminate in the composite material hole extrusion finite element model.

[0121] The failure judgment module 830 is configured to determine a failure material unit according to the material stress of the material units and a preset failure criterion, and perform material performance reduction processing on the failure material unit based on a failure mode.

[0122] The animation generation module 840 is configured to, if the extrusion process ends, determine a stress distribution animation of the hole wall region according to the material stress of the material units, and display composite material hole extrusion damage information according to the stress distribution animation.

[0123] Optionally, the model determination module 810 is specifically configured to:

[0124] determine an anisotropic constitutive model of the composite material laminate according to a layer direction, a layer thickness of the composite material laminate, and tensile elastic modulus, shear elastic modulus and Poisson's ratio corresponding to the layer direction;

[0125] determine geometric models of the composite material laminate, the mandrel and the bushing according to a size, a layer thickness of the composite material laminate, geometric parameters of the hole, the anisotropic constitutive model, geometric parameters and models of the mandrel and the bushing;

[0126] determine the composite material hole extrusion finite element model based on the geometric models of the composite material laminate, the mandrel and the bushing, preset assembly parameters and boundary conditions of the extrusion process.

[0127] Optionally, the preset assembly parameters include extrusion displacement increments corresponding to each time step in the extrusion process.

[0128] The stress determination module 820 is specifically configured to:​

[0129] determine a strain increment of the current time step according to the extrusion displacement increment corresponding to the current time step and an anisotropic constitutive model, wherein the anisotropic constitutive model comprises a stiffness matrix and a compliance matrix of the material unit;

[0130] determine a material strain of the current time step according to a material strain of a previous time step of the material unit and the strain increment of the current time step;

[0131] determine a material stress corresponding to each time step in the extrusion process according to a material strain corresponding to each time step in the extrusion process.

[0132] Optionally, the failure determination module 830 is specifically configured to:

[0133] determine a failure state and a failure mode corresponding to the current time step of the material unit according to a failure determination logic corresponding to the preset failure criterion and the material stress corresponding to the current time step, wherein the failure state represents whether the material unit is failed;

[0134] if the material unit is a failed material unit, determine a degradation factor of the failed material unit according to the failure mode, and update the stiffness matrix and the compliance matrix of the failed material unit according to the degradation factor, so as to update an anisotropic constitutive model corresponding to a next time step;

[0135] if the material unit is a non-failed material unit, the anisotropic constitutive model corresponding to the current time step is taken as an anisotropic constitutive model corresponding to a next time step.

[0136] Optionally, the determination of the material stress corresponding to each time step in the extrusion process according to the material strain corresponding to each time step in the extrusion process comprises:

[0137] determine the material stress of the material unit corresponding to each time step according to the material strain corresponding to each time step and the stiffness matrix.

[0138] Optionally, the determination of the anisotropic constitutive model of the composite laminated plate according to the ply direction, the ply thickness and the tensile and compressive elastic modulus, the shear elastic modulus and the Poisson's ratio corresponding to the ply direction comprises:

[0139] determine the stiffness matrix and the compliance matrix according to the ply direction, the ply thickness and the tensile and compressive elastic modulus, the shear elastic modulus and the Poisson's ratio corresponding to the ply direction of the composite laminated plate;

[0140] If an angle between a main axis direction of a ply of at least one composite layer in the composite laminate and a main axis direction of a target part corresponding to the composite laminate is not zero, a coordinate conversion matrix is determined according to the angle;

[0141] An anisotropic constitutive model of the composite laminate is determined according to the coordinate conversion matrix, the stiffness matrix and the flexibility matrix.

[0142] Optionally, the animation generation module 840 is specifically configured to:

[0143] If the extrusion process ends, the material stress corresponding to each time step of the material unit is obtained;

[0144] A stress distribution diagram of the hole wall region is generated according to the material stress corresponding to each time step, and the stress distribution diagrams are spliced according to the sequence of the time steps to obtain a stress distribution animation of the hole wall region.

[0145] The extrusion damage prediction device provided in the embodiments of the present application can execute the extrusion damage prediction method provided in any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0146] Figure 9 A structural schematic diagram of an electronic device is provided for the embodiments of the present application. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0147] As shown in Figure 9 The electronic device 10 includes at least one processor 11, and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which is communicatively connected to the at least one processor 11, wherein the memory stores a computer program executable by the at least one processor. The processor 11 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0148] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0149] The processor 11 can be various general and / or special purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the crush damage prediction method.

[0150] In some embodiments, the crush damage prediction method can be implemented as a computer program tangibly embodied in a computer readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded onto the RAM 13 and executed by the processor 11, one or more steps of the crush damage prediction method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the crush damage prediction method by any other appropriate means, such as by means of firmware.

[0151] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a complex programmable logic device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0152] Computer programs for implementing the methods of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program, when executed, can cause instructions defined in the flow charts and / or block diagrams to be implemented. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, and partially on a remote machine or entirely on a remote machine or server.

[0153] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0154] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0155] The systems and techniques described herein can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described herein, or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0156] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0157] It should be understood that the various forms of flow shown above can be re-ordered, added to, or deleted from without departing from the scope of the present disclosure. For example, the steps recited in the present disclosure can be performed in parallel, in series, or in a different order, and the present disclosure is not limited herein as long as the desired results of the technical solutions of the present disclosure can be achieved.

[0158] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for predicting extrusion damage, characterized in that: include: Determining a composite material hole extrusion finite element model, wherein the composite material hole extrusion finite element model includes a geometric model of the composite material laminate, and the geometric model includes material elements in the hole wall area; determining the material stress of the material unit during the extrusion process based on the material properties of the composite laminate in the composite hole extrusion finite element model; Determine a failed material unit according to the material stress of the material unit and a preset failure criterion, and perform material property reduction processing on the failed material unit based on the failure mode; If the extrusion process is completed, a stress distribution animation of the hole wall region is determined according to the material stress of the material unit, and extrusion damage information of the composite material hole is displayed according to the stress distribution animation.

2. The method according to claim 1, characterized in that Determining the composite material hole extrusion finite element model includes: Determining an anisotropic constitutive model of the composite laminate according to the ply direction, ply thickness, and the tensile and compressive elastic moduli, shear elastic modulus, and Poisson's ratio corresponding to the ply direction; Determining the geometric models of the composite laminate, the core rod, and the bushing according to the size of the composite laminate, the ply thickness, the geometric parameters of the opening, the anisotropic constitutive model, and the geometric parameters and models of the core rod and the bushing; A composite hole extrusion finite element model is determined based on the geometric models of the composite laminate, core rod and bushing, preset assembly parameters and boundary conditions of the extrusion process.

3. The method according to claim 2, characterized in that The preset assembly parameters include the extrusion displacement increment corresponding to each time step in the extrusion process; Determining the material stress of the material unit during the extrusion process according to the material properties of the composite material laminate in the composite material hole extrusion finite element model includes: determining a strain increment for the current time step based on an extrusion displacement increment corresponding to the current time step and an anisotropic constitutive model, wherein the anisotropic constitutive model includes a stiffness matrix and a compliance matrix of the material unit; Determining the material strain of the current time step based on the material strain of the material unit at the previous time step and the strain increment of the current time step; The material stress corresponding to each time step is determined according to the material strain corresponding to each time step in the extrusion process.

4. The method according to claim 3, characterized in that The determining of a failed material unit according to the material stress of the material unit and a preset failure criterion, and performing material property reduction processing on the failed material unit based on the failure mode, includes: Determining a failure state and a failure mode of the material unit corresponding to the current time step according to a failure judgment logic corresponding to the preset failure criterion and a material stress corresponding to the current time step, wherein the failure state indicates whether the material unit has failed; If the material unit is a failed material unit, determining a degradation factor of the failed material unit according to the failure mode, and updating the stiffness matrix and the flexibility matrix of the failed material unit according to the degradation factor to update the anisotropic constitutive model corresponding to the next time step; If the material unit is a non-failed material unit, the anisotropic constitutive model corresponding to the current time step is used as the anisotropic constitutive model corresponding to the next time step.

5. The method according to claim 3, characterized in that Determining the material stress corresponding to each time step according to the material strain corresponding to each time step in the extrusion process includes: The material stress corresponding to each time step of the material unit is determined according to the material strain corresponding to each time step and the stiffness matrix.

6. The method according to claim 2, characterized in that Determining the anisotropic constitutive model of the composite laminate according to the ply direction, ply thickness, and the tensile and compressive elastic modulus, shear elastic modulus, and Poisson's ratio corresponding to the ply direction of the composite laminate comprises: Determine a stiffness matrix and a flexibility matrix according to a ply direction, a ply thickness, and tensile and compressive elastic moduli, shear elastic moduli, and Poisson's ratio corresponding to the ply directions of the composite laminate; If an angle between a principal axis direction of at least one composite material layer in the composite material laminate and a principal axis direction of a target component corresponding to the composite material laminate is not zero, determining a coordinate transformation matrix according to the angle; An anisotropic constitutive model of the composite laminate is determined according to the coordinate transformation matrix, the stiffness matrix and the flexibility matrix.

7. The method according to claim 1, characterized in that If the extrusion process is completed, the stress distribution animation of the hole wall area is determined according to the material stress of the material unit, including: If the extrusion process is completed, the material stress corresponding to each time step of the material unit is obtained; A stress distribution diagram of the hole wall region is generated according to the material stress corresponding to each time step, and the stress distribution diagrams are spliced ​​according to the sequence of the time steps to obtain a stress distribution animation of the hole wall region.

8. A device for predicting crush damage, characterized in that: include: a model determination module, configured to determine a composite material hole extrusion finite element model, wherein the composite material hole extrusion finite element model comprises a geometric model of the composite material laminate, and the geometric model comprises material units in a hole wall region; a stress determination module for determining the material stress of the material unit during the extrusion process according to the material properties of the composite laminate in the composite hole extrusion finite element model; a failure judgment module, configured to determine a failed material unit according to the material stress of the material unit and a preset failure criterion, and perform material performance reduction processing on the failed material unit based on the failure mode; The animation generation module is used to determine the stress distribution animation of the hole wall area according to the material stress of the material unit when the extrusion process is completed, and to display the composite material hole extrusion damage information according to the stress distribution animation.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for predicting crush damage according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method for predicting crush damage according to any one of claims 1 to 7 when executed.

11. A computer program product, characterized in that The computer program product comprises a computer program, which, when executed by a processor, implements the method for predicting crush damage according to any one of claims 1 to 7.

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