Composite structure failure prediction analytical method

Abstract

The invention provides a composite structure failure prediction analytical method. The constitutive equation expressing the stress-strain relation of an anisotropic composite under the influences of damp-heat environments is established through the combination of influences of damp-heat strain. Meanwhile, through the combination with an asymptotic damage analysis method, the influences of damp-heat effects on parameters such as rigidity and strength of materials are introduced to the three aspects of a stress analysis mode, a failure criterion and a material degradation model, a UMAT subprogram is complied, packaged and embedded in finite element software, and finally a more perfect asymptotic damage model capable of being used for composite failure analysis under the damp-heat environments is established. Compared with an existing failure asymptotic damage analysis method for various composite structures, the influences of damp-heat effects on failure behaviors of anisotropic composites are considered, the damage process of materials under damp-heat environments can be accurately expressed, and the composite structure failure prediction analytical method is suitable for prediction of simulation and strength of the composite structure damage process under the condition that temperature, humidity and other conditions are more complex.

Description

technical field [0001] The invention relates to the technical field of composite material structure failure analysis, in particular to a composite material structure failure prediction analysis method considering the influence of hygrothermal effect factors, which is applicable to various complex fiber-reinforced resin-based composite material structures widely used at present. Background technique [0002] Advanced composite materials have many excellent characteristics such as high specific strength and specific modulus, tailorable design and easy overall forming, which can significantly reduce the weight of aircraft structures and improve the safety, economy, comfort and environmental protection of aircraft. The scope of application has been expanded from the original non-bearing structure, secondary load-bearing structure to the main load-bearing structure. At present, the amount and application position of advanced composite materials in the aircraft body structure has ...

AI Technical Summary

Problems solved by technology

In general, high temperature and humid environments will significantly weaken the mechanical properties of the matrix and fibers, leading to extremely complex failure processes and degradation behaviors of composites

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