Impact compression behaviors of 3D angle-interlock woven composites under thermo-oxidative ageing

Impact compression behaviors after thermo-oxidative ageing are key to design safety and durability of 3D angle-interlock woven composites (3DAWC). This paper experimentally and numerically presents the impact compression properties and damage morphology of composites before and after ageing, which reveals the effects of thermo-oxidative ageing on impact compression behaviors of 3DAWC. The testing results revealed that the composites impact compression mechanical properties, i.e., maximum stress and modulus, decrease with the increasing ageing time. The impact compression properties degradation of 3DAWC is attributed to the epoxy resin degradation and interface debonding. Moreover, the interfacial debonding hinders the propagation of stress waves. The finite element analysis (FEA) results illustrate the ageing interfacial damage changes the crack propagation path during impact compression. The matrix degradation and interfacial weakening after ageing aggravate the interfacial damage and reduce the stress distribution of aged composites. The failure morphology of aged composites is more serious.