Multi-dimensional predicting method for strength of braided ceramic base composite material

Abstract

The invention provides a multi-dimensional predicting method for strength of a braided ceramic base composite material. Firstly a parameterization method is used for establishing a braided ceramic base composite material single-cell model which comprises yarns and a matrix, and then period grid dividing is performed. Afterwards a mesomechanics method is used for simulating the mechanics behavior of the yarn unit. Furthermore a strain conversion matrix is used for converting a yarn element stiffness matrix from a local coordinate system to an integral coordinate system. Finally through applyingan increment type periodic boundary condition, a micro-stress and a strain field of a single cell are calculated. A volume averaging method is used for obtaining a microscopic stress and strain of the braided ceramic base composite material. If a failure unit band which penetrates through the single cell is formed, failure of the braided ceramic base composite material is determined, and the single-cell average stress is the strength of the braided ceramic base composite material. According to the multi-dimensional predicting method, the multidimensional analysis method in which macrography and mesography are combined is utilized. The strength of the braided ceramic base composite material can be accurately predicted without dependence to a large number of experiments with time consumption and high cost.

Description

technical field [0001] The invention belongs to the technical field of composite material strength prediction methods, and in particular relates to a multi-scale prediction method for the strength of braided ceramic matrix composite materials. Background technique [0002] Ceramic matrix composites have many advantages such as high specific stiffness, high specific strength, high temperature resistance, corrosion resistance, low density, etc., and have broad application prospects in the hot end parts of aviation, aerospace, nuclear power and other industries. Ceramic matrix composites can generally be divided into unidirectional, laminated, and braided forms according to their yarn structure. In engineering applications, ceramic matrix composite structural parts are generally braided structures. In order to apply ceramic matrix composites more efficiently and safely, it is necessary to predict the strength of braided ceramic matrix composites. [0003] The mesoscopic geome...

AI Technical Summary

Problems solved by technology

However, this method is a phenomenological analysis method that relies on test results and cannot analyze the mesoscopic failure process of braided ceramic matrix composites.

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