A Failure Analysis Method for Composite Structures Based on Continuum Damage Mechanics Degradation Model

Abstract

The invention relates to a composite material structure failure analysis method based on a continuum damage mechanics degradation model. According to the method, a three-dimensional continuum damage mechanics degradation model of a unidirectional fiber enhanced composite material is constructed, two types of damage forms such as fiber cracks and matrix cracks and the orientation of damages are considered, and meanwhile, the crack closure effect caused by coupling of the fiber damage and the matrix damage and reverse loading of load in a fiber stretching and compressing damage process is considered; three damage variables are respectively used for representing the fiber crack damage and two mutually-perpendicular matrix crack damages respectively, so that the continuum damage mechanics degradation model for failure analysis of a composite material structure is obtained. Compared with the conventional anti-climax degradation model, the continuum damage mechanics degradation model has the advantages that the behavior characteristics of the damaged composite material under different load states are considered, and the performance of the damaged material can be accurately represented; the composite material structure failure analysis method is suitable for simulation of a composite material structure damage process and forecasting of the intensity under a condition that the load state and a constraint situation are more complicated.

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 analysis method based on a continuous damage mechanics degradation model, which is applicable to various complex composite material structures widely used in aerospace vehicles. 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 become an important indicator...

Images