CN-121678374-B - Inversion method of ceramic matrix composite temperature-related mechanical properties

CN121678374BCN 121678374 BCN121678374 BCN 121678374BCN-121678374-B

Abstract

The application discloses an inversion method of temperature-related mechanical properties of a ceramic matrix composite material, and particularly relates to the field of composite material performance characterization. The method comprises the steps of dividing a ceramic matrix composite to be tested into a plurality of test pieces, heating each test piece to a target temperature to obtain actual measurement thermal strains of a plurality of points on the surface of each test piece, uniaxially stretching the test piece through a loading end at the target temperature of each test piece, obtaining actual measurement tensile strain curves and actual measurement stress strain curves of the plurality of points on the surface of the test piece in the uniaxial stretching process, constructing a parameterization function of mechanical property parameter vectors of the ceramic matrix composite to be tested along with temperature change, taking a minimized error function as a target, carrying out inversion identification on the super parameter vectors to obtain optimal super parameter vectors, and combining the parameterization function to obtain the mechanical property parameter vectors of the ceramic matrix composite to be tested. Based on the method, the mechanical property parameters of the micro-scale component material can be obtained.

Inventors

HUANG SHENG
RONG LE
JIANG ZHUOQUN
WANG ZHANXUE
ZHOU LI
SHI JINGWEI
DENG WENJIAN

Assignees

西北工业大学

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (8)

1. The inversion method of the temperature-related mechanical properties of the ceramic matrix composite is characterized by comprising the following steps of: Heating each test piece to a target temperature, wherein the target temperature corresponding to each test piece is different; acquiring actual measurement thermal strain of a plurality of points on the surface of each test piece at a corresponding target temperature; for each test piece, uniaxially stretching the test piece through a loading end at the target temperature, obtaining actual measurement tensile strain of a plurality of points on the surface of the test piece in the uniaxial stretching process, loading and displacement of the loading end, and determining an actual measurement stress strain curve according to the loading, displacement and the actual measurement tensile strain; Constructing a parameterized function of the mechanical property parameter vector of the ceramic matrix composite to be tested along with the temperature change, wherein the parameterized function comprises a temperature and a super parameter vector serving as a coefficient, and the mechanical property parameter vector comprises a matrix elastic modulus, a matrix thermal expansion coefficient, a fiber bundle longitudinal elastic modulus, a fiber bundle transverse elastic modulus and a fiber bundle longitudinal thermal expansion coefficient; Performing inversion identification on the super-parameter vector by taking the minimized error function as a target to obtain an optimal super-parameter vector; inputting the optimal super-parameter vector and temperature into a parameterization function to obtain a mechanical property parameter vector of the ceramic matrix composite to be tested; The error function is determined according to the difference between the predicted thermal strain and the actually measured thermal strain, the difference between the predicted stress strain curve and the actually measured stress strain curve, and the difference between the predicted tensile strain and the actually measured tensile strain; The predicted thermal strain, the predicted stress strain curve and the predicted tensile strain are obtained by inputting a super-parameter vector into a pre-trained prediction model; the parameterized function is: in the formula, The super-parameter vector is composed of the ith mechanical property parameter in the mechanical property parameter vector, T is temperature, and A i 、B i 、C i is coefficient.
2. The inversion method of temperature-dependent mechanical properties of a ceramic matrix composite according to claim 1, wherein the error function is: in the formula, For super-parametric vectors, omega 1 、ω 2 、ω 3 are weight coefficients, As an error term in the thermal expansion, Is the error term of the macroscopic mechanics, Is a local strain field error term.
3. The inversion method of temperature-dependent mechanical properties of a ceramic matrix composite according to claim 2, wherein the thermal expansion error term is determined by predicting the difference between the thermal strain and the measured thermal strain: in the formula, Is the measured thermal strain at the jth point of the kth test piece surface, T is the temperature, Is the predicted thermal strain for the jth point of the kth specimen surface.
4. The inversion method of temperature-dependent mechanical properties of a ceramic matrix composite according to claim 2, wherein the macroscopic mechanical error term is determined by the difference between the predicted stress-strain curve and the measured stress-strain curve: in the formula, Is the measured stress-strain curve of the kth test piece, Is the predicted stress-strain curve for the kth test piece, The maximum stress in the measured stress-strain curve of the kth test piece; To integrate the difference between the measured stress-strain curve and the predicted stress-strain curve at each strain ε.
5. The inversion method of temperature-dependent mechanical properties of a ceramic matrix composite according to claim 2, wherein the local strain field error term is determined by predicting the difference between the tensile strain and the measured tensile strain: in the formula, Is the measured tensile strain at the jth point of the kth specimen surface, The predicted tensile strain for the jth point of the kth specimen surface.
6. The inversion method of temperature-dependent mechanical properties of a ceramic matrix composite according to claim 1, wherein performing inversion identification on the super-parametric vector with the objective of minimizing an error function to obtain an optimal super-parametric vector comprises: And taking the super-parameter vector as an individual, calculating a fitness value according to an error function, performing iterative optimization on the super-parameter vector through a differential evolution algorithm to obtain an optimized result, and performing optimization on the optimized result through a Nelder-Mead algorithm to obtain an optimal super-parameter vector.
7. The method for inverting the temperature-dependent mechanical properties of a ceramic matrix composite according to claim 1, wherein the training process of the pre-trained predictive model comprises: Establishing a finite element model of the ceramic matrix composite to be tested, and respectively endowing the finite element model with the material properties of fiber bundles and a matrix; Sampling the super-parameter vectors in a preset range to obtain a plurality of super-parameter vectors; inputting each super-parameter vector into a finite element model of the ceramic matrix composite to be tested to perform finite element calculation to obtain a thermal strain curve, a stress strain curve and a tensile strain; And taking the super-parameter vector as input, and taking corresponding thermal strain, stress strain curve and tensile strain as output, and training the neural network proxy model to obtain a pre-trained prediction model.
8. An inversion device for temperature-dependent mechanical properties of a ceramic matrix composite, comprising: The test measurement module is used for dividing the ceramic matrix composite to be tested to obtain a plurality of test pieces, heating each test piece to a target temperature, wherein the target temperature corresponding to each test piece is different, acquiring actual measurement thermal strain of a plurality of points on the surface of each test piece at the corresponding target temperature, uniaxially stretching the test piece through a loading end at the target temperature of each test piece, acquiring actual measurement tensile strain of a plurality of points on the surface of the test piece in the uniaxial stretching process, loading and displacement of the loading end, and determining an actual measurement stress strain curve according to the loading, displacement and the actual measurement tensile strain; The parameterized function construction module is used for constructing a parameterized function of the mechanical property parameter vector of the ceramic matrix composite to be tested along with the temperature change, wherein the parameterized function comprises temperature and a super-parameter vector serving as a coefficient; The inversion identification module is used for carrying out inversion identification on the super-parameter vector by taking the minimized error function as a target to obtain an optimal super-parameter vector; The error function is determined according to the difference between the predicted thermal strain and the actually measured thermal strain, the difference between the predicted stress strain curve and the actually measured stress strain curve, and the difference between the predicted tensile strain and the actually measured tensile strain; the predicted thermal strain, predicted stress-strain curve, and predicted tensile strain are obtained by inputting a hyper-parametric vector into a pre-trained predictive model.

Description

Inversion method of ceramic matrix composite temperature-related mechanical properties Technical Field The application relates to the field of composite material performance characterization, in particular to an inversion method of ceramic matrix composite material temperature-related mechanical properties. Background The ceramic matrix composite material is a material which is composed of fiber bundles, a matrix and other component materials and has the characteristics of complex multi-scale structures and mechanical properties, and has wide application prospects in extreme environments (such as hot end components and thermal protection systems of aerospace equipment). However, the complex manufacturing process and inherent multi-scale heterostructure of the ceramic matrix composite lead to very complex anisotropic mechanical properties, and the influence of the high-temperature environment on the micro-component properties of the ceramic matrix composite leads to the same complex law of the mechanical properties of the ceramic matrix composite along with the temperature change, which greatly limits the engineering application of the ceramic matrix composite in high-temperature parts. The traditional measurement technology is difficult to carry out high-efficiency and comprehensive measurement on the anisotropic microscopic mechanical properties of the ceramic matrix composite material, and only limited macroscopic-scale performance parameters can be obtained through experimental methods such as stretching, compression, shearing and the like, so that the mechanical performance parameters of the microscopic-scale component material cannot be obtained. In addition, the difficulty of experimental measurement in a high-temperature environment increases the measurement cost, so that the temperature-related mechanical properties of the ceramic matrix composite material cannot be obtained. Disclosure of Invention The application mainly aims to provide an inversion method of temperature-related mechanical properties of a ceramic matrix composite material, and aims to solve the problem that the existing method cannot obtain mechanical property parameters of a micro-scale component material. In order to achieve the aim, the application provides an inversion method of the temperature-related mechanical properties of a ceramic matrix composite material, which comprises the steps of dividing the ceramic matrix composite material to be tested to obtain a plurality of test pieces; the method comprises the steps of heating each test piece to a target temperature, obtaining actual measurement thermal strain of a plurality of points on the surface of each test piece at the corresponding target temperature, uniaxially stretching the test piece through a loading end at the target temperature of each test piece, obtaining actual measurement tensile strain of a plurality of points on the surface of the test piece in the uniaxial stretching process, loading and displacement of the loading end, determining an actual measurement stress strain curve according to the loading, displacement and actual measurement tensile strain, constructing a parameterization function of mechanical property parameter vectors of a ceramic matrix composite material to be tested, wherein the parameterization function comprises temperature and super parameter vectors serving as coefficients, inverting and identifying the super parameter vectors by taking a minimized error function as a target, obtaining the optimal super parameter vectors, inputting the optimal super parameter vectors and the temperature into the parameterization function, obtaining the mechanical property parameter vectors of the ceramic matrix composite material to be tested, wherein the error function is determined according to the difference between the predicted thermal strain and the actual measurement thermal strain, the difference between the predicted stress strain curve and the actual measurement stress strain curve, and the difference between the predicted tensile strain and the actual measurement tensile strain, and the predicted tensile strain are obtained by inputting the predicted thermal strain and predicted tensile strain and the predicted tensile strain into a predicted parameter model. Optionally, the parameterized function is: in the formula, The super-parameter vector is composed of the ith mechanical property parameter in the mechanical property parameter vector, T is temperature, and A i、Bi、Ci is coefficient. Optionally, the error function is: in the formula, For super-parametric vectors, omega 1、ω2、ω3 are weight coefficients,As an error term in the thermal expansion,Is the error term of the macroscopic mechanics,Is a local strain field error term. Optionally, the thermal expansion error term is determined by predicting a difference in thermal strain from the measured thermal strain: in the formula, Is the measured thermal strain at the jth point of the kth test pi