Multi-mode failure judgment method suitable for transverse isotropic carbon fibers

Abstract

The invention belongs to the field of fracture mechanics, and discloses a multi-mode failure judgment method suitable for transverse isotropic carbon fibers, which comprises the following steps: (1) judging the failure form of the transverse isotropic fibers; (2) constructing a fiber shearing and bending failure stress criterion basic model; (3) judging the sign of the normal stress of the failure surface; (4) solving an undetermined coefficient in the basic form by considering a normal stress symbol of a failure surface under fiber shearing and bending failure states respectively; and (5) establishing a finite element model to verify the accuracy of the model. According to the method disclosed by the invention, the axial/transverse performance difference of the fiber and the influence of the normal stress sign of the failure surface on the shearing and bending failure stress state are considered for the first time, so that the failure of the carbon fiber in various loading processes can be accurately judged. The derivation process is simple, program codes are conveniently generated, and the application of the method is beneficial for further improving the prediction precision of the design performance of the composite material component.

Description

technical field [0001] The invention belongs to the field of fracture mechanics and relates to a multi-mode failure judgment method applicable to transversely isotropic carbon fibers. Background technique [0002] Carbon fiber reinforced resin-based composite materials (hereinafter referred to as "composite materials") are lightweight and high-strength, and have become the preferred materials for weight reduction and efficiency enhancement of new-generation high-end equipment in the fields of aerospace, energy, and transportation. Compared with widely used lightweight high-performance alloys, an irreplaceable advantage of composite materials lies in their excellent designability. That is to say, facing the actual bearing requirements of the components, the structural efficiency of the components can be greatly improved by rationally designing the angle and sequence of the layers, so as to achieve the purpose of simplifying the structure of the components and further reducing...

AI Technical Summary

Problems solved by technology

However, the derivation of this method is based on the assumption of isotropy of fibers, which is not applicable to a class of transversely isotropic carbon fibers made of pitch; The influence of the surface normal stress sign on the failure state still has a large room for improvement in the judgment accuracy of fiber failure

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