Progressive damage model-based full-SiC composite material multi-nail connection structure failure analysis method

Abstract

The invention relates to a progressive damage model-based full-SiC composite multi-nail connection structure failure analysis method. The method comprises the following steps of: (1) establishing a bilinear constitutive model of materials on the basis of C / SiC composite material mechanical property test; (2) establishing a composite material structure three-dimensional finite element model according to a C / SiC composite material multi-nail connection structure geometric parameter; (3) carrying out stress analysis on the basis of the composite material structure three-dimensional finite elementmodel; (4) predicting failure states of the composite materials by applying a failure criterion suitable for C / SiC composite materials; (5) carrying out material rigidity degeneration on the failurematerials according to a degeneration model; and (6) judging whether damages in the composite materials cause structure damage or not, and if the judging result is negative, continuously carrying outloading until the materials fail. The method is suitable for engineering application, and is capable of effectively analyzing and predicting the failure of C / SiC composite material multi-nail connection structures, remarkably reducing the test cost and providing references for engineering practices.

Description

technical field [0001] The invention relates to the technical field of failure analysis of full-SiC composite material structures, in particular to a method for failure analysis of full-SiC composite multi-nail connection structures based on an asymptotic damage model, which is applicable to full-SiC composite multi-nail joints used in hypersonic aircraft connection structure. Background technique [0002] Carbon fiber reinforced silicon carbide ceramic matrix composites (carbon fiber reinforced silicon carbide, C / SiC) has a series of excellent properties such as high strength, high hardness, high temperature resistance, ablation resistance and low density, and has become a promising prospect in the aerospace field. A new generation of high temperature thermal structure. [0003] The various parts in the aircraft need to be connected to form a whole. Due to the weaving process of C / SiC composite materials, it is difficult and expensive to manufacture large and complex struc...

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Problems solved by technology

[0005] However, most of the current analysis of the mechanical connection structure of C / SiC composites is still in the experimental means, and there are few studies on the use of numerical methods to predict the failure of C / SiC composite joints.

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