Finite element modeling on fracture toughness of 3D angle-interlock woven carbon/epoxy composites at microstructure level

Abstract

Fracture toughness behaviors of 3D angle-interlock woven composites were characterized with Mode I double cantilever beam test and finite element analysis (FEA). Load–displacement curves, strain energy release rates and fracture morphologies were obtained from tests and compared with FEA. We found that the 3D woven fabric structure increases strain energy release rates. The pullout and breakages of the yarns through thickness direction are the main mechanisms for the higher fracture toughness than laminates. The tradeoff between higher fracture toughness and lower in-plane stiffness should be considered for designing the 3D woven composites.