Abstract

Due to high specific strength, specific stiffness and flexibility in their design, braid composites have been widely used in various engineering structures. In the practical engineering application, braid composites are in a multidirectional stress state in most cases, in which the material failure mechanism is very complex. Moreover, the performance degradation of stiffness and strength is more complex. The microstructure of 3D braided composites is extremely complicated and shows intensive inhomogeneity and anisotropy, which results in considerable difficulties in the researches of macro-meso-mechanical properties and damage mechanics. This review summarized different research methods such as prediction of strength, lowvelocity impact and fatigue failure.

Keywords: Braid composites; Stress state; Failure mechanism; Tensile load; Low-velocity impact