CN117804903A - Method, device, equipment and storage medium for testing in-plane compression modulus - Google Patents
Method, device, equipment and storage medium for testing in-plane compression modulus Download PDFInfo
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Abstract
The application relates to a method, a device, equipment and a storage medium for testing in-plane compression modulus, wherein the method for testing in-plane compression modulus comprises the following steps: paving the prepreg on a die with a bending structure, and performing deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg is defective; simulating the experimental process of deformation and pressure test through a finite element model to respectively obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus; fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure; substituting the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value, and determining the in-plane compression modulus of the prepreg according to the compression modulus calculation value. The method and the device can solve the problem that the in-plane compression modulus of the prepreg is difficult to measure.
Description
Technical Field
The application relates to the technical field of composite material prepreg mechanical property testing, in particular to a method, a device, equipment and a storage medium for testing in-plane compression modulus.
Background
The composite material has the characteristics of high specific stiffness, high specific strength, corrosion resistance, good vibration damping performance, designable structural mechanical property and the like, and has wide application in the aerospace field. In the process of forming the composite material, the resin undergoes the change of viscous state, rubbery state and glassy state, and the material parameters continuously change along with the process temperature and pressure, so that various manufacturing defects such as pores, layering, deformation, dimension out-of-tolerance, wrinkles and the like can be generated due to the reasons of mismatching of the material parameters, process control precision and the like. Theoretical analysis, numerical simulation and experimental test studies have been conducted for the cause and influencing parameters of defect formation, which generally require in-plane compression modulus of the composite prepreg as an input parameter. However, since the flexural rigidity of the prepreg before curing is very low, its modulus cannot be measured by a conventional material compression property test method, and thus there is no effective method for directly testing the in-plane compression modulus of the prepreg.
Accordingly, the inventors provide a method, apparatus, device, and storage medium for testing in-plane compression modulus.
Disclosure of Invention
(1) Technical problem to be solved
The embodiment of the application provides a method, a device, equipment and a storage medium for testing in-plane compression modulus, which can solve the problem that no effective method for directly testing the in-plane compression modulus of prepreg exists in the prior art.
(2) Technical proposal
In a first aspect, embodiments of the present application provide a method for testing in-plane compression modulus, including:
paving the prepreg on a die with a bending structure, and performing deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg is defective;
simulating the experimental process of deformation and pressure test through a finite element model to respectively obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus;
fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure;
substituting the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value;
substituting the compression modulus calculated value as a preset compression modulus into an experimental process of simulating deformation and pressure test by a finite element model to obtain a critical pressure calculated value when the prepreg generates defects under the compression modulus calculated value;
and determining the compression modulus calculation value as the in-plane compression modulus of the prepreg when the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
In one embodiment, the prepreg comprises a carbon fiber reinforced epoxy prepreg.
In one embodiment, the curved structure comprises an L-shaped structure comprising a circular R-region.
In one embodiment, the method comprises the steps of paving the prepreg on a die of a bending structure, and before performing deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg generates defects, further comprising:
performing a thickness direction compression performance test on the prepreg to obtain the thickness direction compression performance of the prepreg;
and (3) performing an interlayer slip performance test on the prepreg to obtain the interlayer slip performance of the prepreg.
In one embodiment, the thickness direction compression performance test, the interlayer slip performance test, and the deformation and pressure test are performed at the same temperature.
In one embodiment, before the experimental process of simulating deformation and pressure test by using the finite element model to obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus, the method further comprises:
and establishing a finite element model according to the size of the prepreg, the size of the die, the compression performance in the thickness direction, the interlayer sliding performance and a plurality of preset compression moduli.
In one embodiment, after substituting the calculated compressive modulus value as the preset compressive modulus value into the experimental process of the finite element model for simulating deformation and pressure test, obtaining the calculated critical pressure value when the prepreg generates defects under the calculated compressive modulus value, the method further comprises:
when the error between the calculated critical pressure value and the test critical pressure value is greater than or equal to a preset threshold value, re-fitting the polynomial function through the calculated compressive modulus value and the calculated critical pressure value;
repeatedly executing the step of substituting the critical pressure test value into the polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value, substituting the compression modulus calculation value as a preset compression modulus into the experimental process of the finite element model simulation deformation and pressure test to obtain a critical pressure calculation value when the prepreg generates defects under the compression modulus calculation value until the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
In a second aspect, embodiments of the present application provide a device for testing in-plane compression modulus, including:
the test module is used for paving the prepreg on a die with a bending structure, and carrying out deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg is defective;
the experiment simulation module is used for simulating the experiment process of deformation and pressure test through the finite element model to respectively obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus;
the function fitting module is used for fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure;
the modulus calculation module is used for substituting the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value;
the pressure calculation module is used for substituting the compression modulus calculation value as a preset compression modulus into an experimental process of the finite element model simulation deformation and pressure test to obtain a critical pressure calculation value when the prepreg generates defects under the compression modulus calculation value;
and the modulus determining module is used for determining the compression modulus calculation value as the in-plane compression modulus of the prepreg when the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
In a third aspect, embodiments of the present application provide an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing a method of testing in-plane compression modulus as described above when the computer program is executed by the processor.
In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program which, when executed by a processor, implements a method of testing in-plane compression modulus as described above.
(3) Advantageous effects
The technical scheme of the application has the following advantages:
according to the method for testing the in-plane compression modulus, provided by the embodiment of the application, the critical pressure test value generated by defects is obtained through the deformation and pressure test of the prepreg, the critical pressure simulation value of the prepreg under each preset compression modulus is obtained through the experimental process of the deformation and pressure test simulated by the finite element model, the polynomial function is fitted according to each preset compression modulus and the critical pressure simulation value, the in-plane compression modulus of the prepreg is obtained through the combination of the critical pressure test value and the polynomial function and the test and the numerical analysis, and the test and the numerical analysis are combined, so that the problem that the in-plane compression modulus of the prepreg is difficult to measure is solved.
It will be appreciated that the advantages of the second, third and fourth aspects may be found in the relevant description of the first aspect and are not repeated here.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for testing in-plane compression modulus provided herein;
FIG. 2 is a schematic diagram of a thickness direction compression performance test provided herein;
FIG. 3 is a schematic diagram of an interlayer slip performance test provided herein;
FIG. 4 is a schematic illustration of deformation and pressure testing provided herein;
FIG. 5 is a schematic structural diagram of an in-plane compression modulus testing device provided by the present application;
fig. 6 is a schematic structural diagram of an electronic device provided in the present application.
Reference numerals: 201. an upper panel and a lower panel; 202. a prepreg sample; 301. fixing the prepreg; 302. sliding the prepreg; 401. a membrane pressure sensor; 402. a mold; 403. a preform.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In addition, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise. "plurality" means "two or more".
At present, the composite material has the characteristics of high specific stiffness, high specific strength, corrosion resistance, good vibration damping performance, designable structural mechanical properties and the like, and has wide application in the aerospace field. In the process of forming the composite material, the resin undergoes the change of viscous state, rubbery state and glassy state, and the material parameters continuously change along with the process temperature and pressure, so that various manufacturing defects such as pores, layering, deformation, dimension out-of-tolerance, wrinkles and the like can be generated due to the reasons of mismatching of the material parameters, process control precision and the like. Wrinkles refer to folds, wrinkles or bending deformations formed in the surface or interior of a composite material by one or more layers of fibers within the composite material, and are relatively serious defects in the composite material forming process. The existence of the folds can cause the change of a structural force transmission path and the local stress concentration, can cause the performance reduction amplitude of the mechanical strength, the fatigue life and the like of the composite material to exceed 30 percent, reduce the bearing capacity of the component, and even cause the scrapping of parts due to serious defects, so that the large economic loss is caused and the overall development progress is influenced.
In order to improve the forming quality of parts, scholars at home and abroad develop theoretical analysis, numerical simulation and experimental test research aiming at fold forming reasons and influencing parameters. The experimental test can give out the influence rules of different processes and structural parameters on the wrinkles, but the forming reason and the forming mechanism of the defects are difficult to explain. Theoretical analysis ignores nonlinear behavior in the structural deformation process based on linear elastic assumption; simplifying the preform into a single-layer structure in the thickness direction, and also failing to consider the relative sliding movement between the prepreg plies; the compressive modulus of the prepreg is generally assumed to be the same as the cured laminate structure during the analysis. In the numerical model, the compression performance in the thickness direction of the material and the interlayer friction performance are obtained through test, and various test methods can be referred to; the in-plane compression properties of the material are also set with reference to the mechanical parameters of the laminate after curing. The lack of effective test and calculation methods determines the in-plane compression modulus of the prepreg in the molding stage, and provides accurate input parameters for theoretical analysis and numerical simulation.
Since the flexural rigidity of the prepreg before curing is very low, its modulus cannot be measured by conventional material compression performance testing methods, and thus there is no effective method to directly test the in-plane compression modulus of the prepreg.
In view of the above problems, the embodiments of the present application provide a method for testing in-plane compression modulus, which includes paving a prepreg on a mold with a curved structure, and performing deformation and pressure testing on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg has defects; simulating the experimental process of deformation and pressure test through a finite element model to respectively obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus; fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure; substituting the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value; substituting the compression modulus calculated value as a preset compression modulus into an experimental process of simulating deformation and pressure test by a finite element model to obtain a critical pressure calculated value when the prepreg generates defects under the compression modulus calculated value; when the error between the critical pressure calculated value and the critical pressure test value is smaller than a preset threshold value, the compression modulus calculated value is determined to be the in-plane compression modulus of the prepreg, so that the in-plane compression modulus of the prepreg before curing can be obtained, input is provided for the molding quality evaluation and defect prediction of the composite material structure, and the method has important significance for raw material evaluation and improvement.
The detailed description of the present application is further described in detail below with reference to the drawings and examples. The following examples are illustrative of the present application, but are not intended to limit the scope of the present application.
As shown in fig. 1, the method for testing in-plane compression modulus provided in this embodiment includes:
s101, paving the prepreg on a die with a bending structure, and carrying out deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg is defective.
In one embodiment, the prepreg comprises a carbon fiber reinforced epoxy prepreg.
In one embodiment, the curved structure comprises an L-shaped structure comprising a circular R-region.
In one embodiment, the method for laying the prepreg on the mold with the bending structure, before performing deformation and pressure test under the process pressure on the prepreg to obtain the critical pressure test value when the prepreg generates defects, further includes: performing a thickness direction compression performance test on the prepreg to obtain the thickness direction compression performance of the prepreg; and (3) performing an interlayer slip performance test on the prepreg to obtain the interlayer slip performance of the prepreg.
In application, the prepreg may be a resin-based composite prepreg, and the reinforcement forms include unidirectional fibers and woven fibers. In order to test the compression modulus of the prepreg surface of the composite material, the compression performance and the interlayer slip performance of the prepreg sample in the thickness direction can be prepared, the compression, slip displacement and loading load are recorded through a sensor of a testing machine, and the compression stress-strain relation and the interlayer friction coefficient are obtained through data processing.
The thickness direction compression performance test is performed on the prepreg to obtain the thickness direction compression performance of the prepreg, wherein the thickness direction compression performance of the prepreg sample is tested by setting the ambient temperature to be 60 ℃ through a thickness direction compression performance test method shown in fig. 2, so that a corresponding stress-strain relation is obtained and is used as a thickness direction material constitutive model. In fig. 2, 201 is an upper and lower panel of the loading tool, which is in direct contact with a prepreg sample 202, and the prepreg sample 202 is formed by laying multiple layers of prepregs.
The interlayer slip performance test is performed on the prepreg to obtain the interlayer slip performance of the prepreg, and the interlayer slip performance can be tested by setting the ambient temperature to be 60 ℃ and using the interlayer slip performance test method shown in fig. 3 to obtain the change of the friction coefficient along with the pressure as a material interlayer contact constitutive model. In fig. 3, 301 is a fixed prepreg, which is fixed on a tool and kept stationary during the test, 302 is a sliding prepreg, which is pulled by a jig to slowly slide between two fixed prepregs 301, and the contact area between the sliding prepreg 302 and the fixed prepreg 301 is kept unchanged during the test.
In application, as shown in fig. 4, the prepreg is laid on a mold with a curved structure, the film pressure sensor 401 may be fixed on the surface of the mold 402 with an L-shaped structure including a circular R region, specifically, the radius of the R region of the L member is 6mm, the length of the straight section is 50mm, then a plurality of layers of prepregs are laid on the film pressure sensor to form a preform 403, after the laying is completed, the preform is packaged, and displacement of the straight section material in the length direction is limited by a stop block during packaging. The two surfaces of the film sensor 401 are respectively contacted with the mold 402 and the preform 403, so that the compressive stress applied to the preform 403 under the action of the process pressure can be monitored, the process pressure, namely the critical pressure when defects occur, can be determined through the change of the compressive stress, and the outer surface of the preform 403 is a vacuum bag for encapsulation.
The above-mentioned deformation and pressure test under the action of technological pressure can be used to obtain the critical pressure test value when the prepreg is defective, and the pre-formed body 403 after being laid can be placed together with mould 402In the hot press apparatus, a process pressure gradually increasing at a constant temperature such as 60 ℃ is applied to the surface of the preform 403, and the change in the compressive stress applied to the preform 403 is monitored by the film pressure sensor 401, to obtain a critical pressure test value at the time of defect generation. The pressure stress and the loading pressure monitored by the film sensor 401 are recorded, defects start to be generated when the pressure stress at the bending part is reduced, and the process pressure P at the moment is extracted 1 The critical pressure test value is obtained.
In one embodiment, the thickness direction compression performance test, the interlayer slip performance test, and the deformation and pressure test are performed at the same temperature.
S102, simulating the experimental process of deformation and pressure test through a finite element model, and respectively obtaining the critical pressure simulation values when the prepreg generates defects under each preset compression modulus.
In one embodiment, before the experimental process of simulating deformation and pressure test by using the finite element model to obtain the critical pressure simulation value when the prepreg generates defects under each preset compression modulus, the method further comprises: and establishing a finite element model according to the size of the prepreg, the size of the die, the compression performance in the thickness direction, the interlayer sliding performance and a plurality of preset compression moduli.
In the application, a finite element analysis model can be established, an initial value of compression modulus in a prepreg surface is set, and an experimental process of deformation and pressure test of the prepreg under the action of process pressure is simulated to obtain a critical pressure simulation value when defects occur. The finite element model is built according to the size of the prepreg, the size of the mold, the compression performance in the thickness direction, the interlayer slip performance and a plurality of preset compression moduli, which may be the same size finite element model built according to the size in the step S101, the mechanical performance in the thickness direction of the prepreg is set according to the compression performance in the thickness direction obtained by the test, the interlayer friction coefficient is set according to the interlayer slip performance obtained by the test, and the compression modulus E of the cured laminate is set 0 Taking E as reference respectively 0 、0.8E 0 、0.6E 0 、0.4E 0 And 0.2E 0 Preset compression modulus E as prepreg p1 ～E p5 . The above-mentioned general purposeThe experimental process of deformation and pressure test is simulated by a finite element model to respectively obtain the critical pressure simulation values when the prepreg generates defects under each preset compression modulus, wherein E can be p1 ～E p5 The experimental process of deformation and pressure test is simulated by a finite element model, and the process pressure value, namely the critical pressure simulation value P, when the defect is generated is obtained c1 ～P c5 。
And S103, fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure.
In application, the fitting of the multiple preset compression moduli and the critical pressure analog values corresponding to the preset compression moduli to obtain the polynomial function between the compression modulus and the critical pressure may be that the compression modulus E pi As an independent variable, critical pressure P ci Fitting using polynomials as dependent variables to obtain polynomial functions The coefficients are obtained by least square method, wherein the formula for calculating the coefficients by least square method can be +.>
S104, substituting the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value.
In application, the above-mentioned critical pressure test value is substituted into polynomial function to obtain compression modulus calculation value corresponding to critical pressure test value, which can be that using polynomial function to calculate critical pressure test value P 1 Corresponding compressive modulus calculation E x 。
S105, substituting the compressive modulus calculated value as a preset compressive modulus into an experimental process of the finite element model simulation deformation and pressure test to obtain a critical pressure calculated value when the prepreg is defective under the compressive modulus calculated value.
In application, the above experimental process of substituting the calculated compressive modulus value as the preset compressive modulus value into the finite element model to simulate deformation and pressure test, to obtain the calculated critical pressure value when the prepreg is defective under the calculated compressive modulus value may be that the calculated compressive modulus value E x Substituting the preset compression modulus into a finite element model, and simulating the experimental process of deformation and pressure test to obtain a process pressure value, namely a critical pressure calculated value P when defects are generated x 。
In one embodiment, substituting the calculated compressive modulus value as the preset compressive modulus value into the experimental process of the finite element model for simulating deformation and pressure test, obtaining the calculated critical pressure value when the prepreg generates defects under the calculated compressive modulus value further comprises: when the error between the calculated critical pressure value and the test critical pressure value is greater than or equal to a preset threshold value, re-fitting the polynomial function through the calculated compressive modulus value and the calculated critical pressure value; repeatedly executing the step of substituting the critical pressure test value into the polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value, substituting the compression modulus calculation value as a preset compression modulus into the experimental process of the finite element model simulation deformation and pressure test to obtain a critical pressure calculation value when the prepreg generates defects under the compression modulus calculation value until the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
In application, if the critical pressure is calculated as P x And the critical pressure test value P 1 The error between the values is greater than or equal to a preset threshold value, such as 5%, and then the value E is calculated through the compression modulus x And critical pressure calculation value P x Fitting the polynomial function again, updating the parameters, repeating steps S104 and S105, iterating for a plurality of times until the critical pressure calculated value P obtained by finite element calculation x Value and critical pressure test value P 1 The error between them is less than a preset threshold, such as 5%.
And S106, determining the compression modulus calculation value as the in-plane compression modulus of the prepreg when the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
In the application, when the error between the calculated value of the critical pressure and the test value of the critical pressure is smaller than the preset threshold value, the calculated value of the compression modulus is determined as the in-plane compression modulus of the prepreg, if the calculated value E of the compression modulus is calculated x Calculated value P of critical pressure x Value and critical pressure test value P 1 The error between the values is smaller than a preset threshold value, such as 5%, and the calculated value E of the compression modulus x The in-plane compression modulus of the prepreg was obtained.
Test tests and numerical calculation are carried out on the T300-grade carbon fiber reinforced epoxy resin fabric prepreg, and the test results show that the pressure in the thickness direction of the R region is reduced when the process pressure is increased to 0.27MPa in the 60 ℃ environment, and the in-plane compression modulus of the prepreg obtained through iterative calculation is 23.5GPa and the process pressure when the corresponding defects occur is 0.262MPa.
According to the method for testing the in-plane compression modulus, the critical pressure test value generated by defects is obtained through the deformation and pressure test of the prepreg, the critical pressure simulation value of the prepreg under each preset compression modulus is obtained through the experimental process of the deformation and pressure test simulated by the finite element model, the polynomial function is fitted according to each preset compression modulus and the critical pressure simulation value, the in-plane compression modulus of the prepreg is obtained through the combination of the critical pressure test value and the polynomial function and the test and the numerical analysis, and the test and the numerical analysis are combined, so that the problem that the in-plane compression modulus of the prepreg is difficult to measure is solved. The method is suitable for unidirectional fiber and woven fiber reinforced resin matrix composite prepreg, and can adjust the test temperature according to the technological parameters to obtain the material performance under different temperature conditions. The method can provide more accurate input parameters for deformation analysis, defect prediction and solidification deformation calculation in the composite material part forming process, improves the numerical model prediction precision, and reduces the test period and the cost.
Corresponding to the method for testing in-plane compression modulus described in the above embodiment, as shown in fig. 5, the present embodiment provides a device for testing in-plane compression modulus, the device 500 for testing in-plane compression modulus comprising:
the experiment testing module 501 is used for paving the prepreg on a die with a bending structure, and carrying out deformation and pressure testing on the prepreg under the action of process pressure to obtain a critical pressure testing value when the prepreg has defects;
the experiment simulation module 502 is configured to simulate an experiment process of deformation and pressure test through a finite element model, and obtain a critical pressure simulation value when the prepreg generates defects under each preset compression modulus;
the function fitting module 503 is configured to fit a plurality of preset compression moduli and critical pressure analog values corresponding to the preset compression moduli respectively, so as to obtain a polynomial function between the compression modulus and the critical pressure;
the modulus calculation module 504 is configured to substitute the critical pressure test value into a polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value;
the pressure calculation module 505 is configured to substitute the calculated compressive modulus value as a preset compressive modulus value into an experimental process of simulating deformation and pressure test by using the finite element model, so as to obtain a calculated critical pressure value when the prepreg generates defects under the calculated compressive modulus value;
the modulus determining module 506 is configured to determine the calculated compressive modulus value as an in-plane compressive modulus of the prepreg when an error between the calculated critical pressure value and the test critical pressure value is less than a preset threshold value.
It should be noted that, because the content of information interaction and execution process between the modules/units is based on the same concept as the method embodiment of the present application, specific functions and technical effects thereof may be referred to in the method embodiment section, and details thereof are not repeated herein.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
The embodiment of the present application further provides an electronic device 600, as shown in fig. 6, including a memory 601, a processor 602, and a computer program 603 stored in the memory 601 and executable on the processor 602, where the processor 602 implements the steps of the method for testing in-plane compression modulus provided in the first aspect when executing the computer program 603.
In application, the electronic device may include, but is not limited to, a processor and a memory, fig. 6 is merely an example of an electronic device and does not constitute limitation of an electronic device, and may include more or less components than illustrated, or combine certain components, or different components, such as an input-output device, a network access device, etc. The input output devices may include cameras, audio acquisition/playback devices, display screens, and the like. The network access device may include a network module for wireless networking with an external device.
In application, the processor may be a central processing unit (Central Processing Unit, CPU), which may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field-programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
In applications, the memory may in some embodiments be an internal storage unit of the electronic device, such as a hard disk or a memory of the electronic device. The memory may in other embodiments also be an external storage device of the electronic device, for example a plug-in hard disk provided on the electronic device, a Smart Media Card (SMC), a secure digital (SecureDigital, SD) Card, a Flash Card (Flash Card), etc. The memory may also include both internal storage units and external storage devices of the electronic device. The memory is used to store an operating system, application programs, boot Loader (Boot Loader), data, and other programs, etc., such as program code for a computer program, etc. The memory may also be used to temporarily store data that has been output or is to be output.
The embodiments of the present application also provide a computer readable storage medium storing a computer program, where the computer program can implement the steps in the above-mentioned method embodiments when executed by a processor.
All or part of the process in the method of the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium and which, when executed by a processor, implements the steps of the method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include at least: any entity or device capable of carrying computer program code to an electronic device, a recording medium, computer Memory, read-Only Memory (ROM), random access Memory (RAM, random Access Memory), electrical carrier signals, telecommunications signals, and software distribution media. Such as a U-disk, removable hard disk, magnetic or optical disk, etc.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative apparatus and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the embodiments of the apparatus described above are illustrative only, and the coupling or direct coupling or communication connection shown or discussed with each other may be through some interfaces, the apparatus may be indirectly coupled or in communication connection, whether in electrical, mechanical or other form.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (10)
1. A method for testing in-plane compression modulus, comprising:
paving the prepreg on a die with a bending structure, and performing deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg is defective;
simulating the experimental process of deformation and pressure test through a finite element model to respectively obtain critical pressure simulation values when the prepreg generates defects under each preset compression modulus;
fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure;
substituting the critical pressure test value into the polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value;
substituting the compressive modulus calculated value as a preset compressive modulus into the finite element model to simulate the experimental process of deformation and pressure test, so as to obtain a critical pressure calculated value when the prepreg generates defects under the compressive modulus calculated value;
and determining the compression modulus calculation value as an in-plane compression modulus of the prepreg when an error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
2. The method of testing in-plane compression modulus of claim 1, wherein the prepreg comprises a carbon fiber reinforced epoxy prepreg.
3. The method of testing in-plane compression modulus of claim 1, wherein the curved structure comprises an L-shaped structure comprising a circular R-zone.
4. The method for testing in-plane compression modulus according to claim 1, wherein the step of laying a prepreg on a mold of a curved structure, and performing deformation and pressure testing under a process pressure on the prepreg, before obtaining a critical pressure test value when the prepreg is defective, further comprises:
performing a thickness direction compression performance test on the prepreg to obtain the thickness direction compression performance of the prepreg;
and performing interlayer slip performance test on the prepreg to obtain the interlayer slip performance of the prepreg.
5. The method for testing in-plane compression modulus according to claim 4, wherein the thickness direction compression performance test, the interlayer slip performance test, and the deformation and pressure test are performed at the same temperature.
6. The method according to claim 4, wherein before the experimental process of simulating the deformation and the pressure test by the finite element model to obtain the critical pressure simulation values when the prepreg generates the defects at the respective preset compression moduli, respectively, the method further comprises:
and establishing a finite element model according to the size of the prepreg, the size of the die, the thickness direction compression performance, the interlayer sliding performance and a plurality of preset compression moduli.
7. The method according to claim 1, wherein substituting the calculated compressive modulus value as a preset compressive modulus value into the finite element model to simulate the experimental process of deformation and pressure test, after obtaining the calculated critical pressure value when the prepreg is defective at the calculated compressive modulus value, further comprises:
re-fitting the polynomial function by the calculated compressive modulus value and the calculated critical pressure value when the error between the calculated critical pressure value and the test critical pressure value is greater than or equal to a preset threshold value;
repeating the step of substituting the critical pressure test value into the polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value, substituting the compression modulus calculation value as a preset compression modulus into the finite element model to simulate the experimental process of deformation and pressure test, and obtaining a critical pressure calculation value when the prepreg generates defects under the compression modulus calculation value until the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
8. A device for testing in-plane compression modulus, comprising:
the experimental test module is used for paving the prepreg on a die with a bending structure, and carrying out deformation and pressure test on the prepreg under the action of process pressure to obtain a critical pressure test value when the prepreg generates defects;
the experiment simulation module is used for simulating the experiment process of deformation and pressure test through a finite element model to respectively obtain critical pressure simulation values when the prepreg generates defects under each preset compression modulus;
the function fitting module is used for fitting a plurality of preset compression moduli and critical pressure simulation values corresponding to the preset compression moduli respectively to obtain a polynomial function between the compression modulus and the critical pressure;
the modulus calculation module is used for substituting the critical pressure test value into the polynomial function to obtain a compression modulus calculation value corresponding to the critical pressure test value;
the pressure calculation module is used for substituting the compression modulus calculation value into the finite element model as a preset compression modulus to simulate the experimental process of deformation and pressure test, so as to obtain a critical pressure calculation value when the prepreg generates defects under the compression modulus calculation value;
and the modulus determining module is used for determining the compression modulus calculation value as the in-plane compression modulus of the prepreg when the error between the critical pressure calculation value and the critical pressure test value is smaller than a preset threshold value.
9. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the method of testing in-plane compression modulus according to any of claims 1 to 7 when executing the computer program.
10. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the method of testing in-plane compression modulus according to any of claims 1 to 7.
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