Unidirectional ceramic matrix composite thermal expansion coefficient prediction method considering damage evolution

Abstract

The invention provides an unidirectional ceramic matrix composite thermal expansion coefficient prediction method considering damage evolution. In the process that the ceramic matrix composite is heated to deform, thermal stress is generated in components to cause damage, and the evolution of the damage further changes the stress distribution of the components, so the macroscopic deformation of the material is changed, and then the coefficient of thermal expansion is affected. Damage such as matrix cracking and interface slippage is considered, the interface forward and reverse slippage lengthcaused by temperature change is calculated, the influence of damage evolution on component stress distribution is considered during material macroscopic deformation calculation, the macroscopic thermal strain and the thermal expansion coefficient of the material are finally obtained through calculation, and the precision of a prediction result can be greatly improved.

Description

technical field [0001] The invention belongs to the field of predicting the mechanical properties of composite materials, and in particular relates to a method for predicting the thermal expansion coefficient of unidirectional ceramic matrix composite materials considering damage evolution. Background technique [0002] Due to the advantages of high temperature resistance and low density, ceramic matrix composites are ideal materials for the hot end parts of aerospace vehicles. As a hot-end component, the ceramic matrix composite structure has a large temperature range during operation, which causes thermal deformation. Therefore, the structural design of ceramic matrix composites requires designers to accurately predict the thermal expansion coefficient of materials. At present, the prediction of the thermal expansion coefficient of unidirectional ceramic matrix composites often adopts the linear elastic method. The general process of this method is as follows: 1) obtain t...

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Problems solved by technology

In fact, during the thermal deformation of ceramic matrix composites, thermal stress will be generated in the components to cause damage, and the evolution of damage will further change the macroscopic deformation of the material, thereby affecting the thermal expansion coefficient. Therefore, only the existing linear elastic method is Unable to accurately predict the coefficient of thermal expansion of unidirectional ceramic matrix composites

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