Effects of thermo-oxidative aging on 3-D deformation field and mechanical behaviors of 3-D angle-interlock woven composites

The effect of thermo-oxidative aging on mechanical properties is a key factor in designing composites structures. This paper aims to explore the effects of thermo-oxidative aging on the mechanical behavior, surface deformation and damage evolution of 3-D angle-interlock woven composites (3DAWC) under compression. A bilinear stressstrain curve with high failure strength and compressive modulus were obtained for the unaged sample. The transition region of the stress-strain curve disappeared for the aged sample due to epoxy resin degradation and cracks. The transition strain decreases as the interface damage starts earlier after thermo-oxidative aging. The surface strain, off-plane displacement and Poisson's ratio distribution show structural correlation during compression. Both the surface average strain and the average Poisson's ratio decrease with aging time. A finite element model has been established to explore the mechanical degradation mechanisms.

Automated summary

This study examines the effects of thermo-oxidative aging on the mechanical properties of 3-D angle-interlock woven composites, revealing a decrease in mechanical performance, earlier onset of interface damage, and a reduction in surface strain and Poisson's ratio with aging. A finite element model was utilized to explore the mechanisms of mechanical degradation.