A Method for Predicting the Stress-Strain Response and Strength of Braided Ceramic Matrix Composites

Abstract

The invention discloses a prediction method for stress-strain response and strength of braided ceramic matrix composite. The method is characterized by comprising the following steps: preparing a beltmatrix fiber bundle with the same in-situ performance as woven CMCs, establishing a unit cell finite element model for the belt matrix fiber bundle, and performing finite element calculation on the unit cell finite element model to obtain the stress-strain response with matrix fiber bundles, and the maximum value of stress on stress-strain curve is strength of woven CMCs.. According to the prediction method for stress-strain response and strength of braided ceramic matrix composite, mechanical properties of fibers, a matrix and a fiber / matrix interface do not need to be used as input quantities; only the mechanical property of the yarn needs to be measured, a large number of component material performance test experiments can be omitted, prediction errors caused by component material performance test dispersity can be avoided, and therefore the efficiency of the prediction process and the accuracy of the prediction result can be greatly improved.

Description

Technical field [0001] The present invention relates to a composite mechanical properties prediction method, particularly a prediction method of stress-strain response and intensity of braided ceramic matrix composite material. Background technique [0002] Ceramic Matrix Composite Composite (CMCS below) has the advantages of high temperature, high ratio strength, high ratio modulus, high-priced gap, and material performance can be designed, is the ideal of high temperature components of next-generation air engine material. Stress-strain response and intensity is the most important two mechanical properties of woven CMCs, as stress-strain responses affect the deformation of the woven CMCS structure, and intensity involves damaging CMCS structural members. [0003] Weaving CMCs constitutes a skeleton of a knitted CMCS due to a cross-connection between the woven CMCs and the yarn. The yarn has a fiber, the interface layer between the substrate, and the fiber / matrix. At present, s...

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Problems solved by technology

However, when using this method, mesoscopic material parameters such as fiber volume fraction, fiber elastic modulus, fiber strength distribution, matrix volume fraction, matrix elastic modulus, matrix strength and interfacial shear strength are required, and the measurement of these parameters requires a large number of There are many tests, and the measurement results are highly dispersed, which makes the process of predicting the stress-strain response and strength of braided CMCs very inefficient, and the accuracy of the prediction results is difficult to guarantee

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