Finite Element Analysis of a Concave 3D Angle‐Interlock Woven Composites Under 60° and 90° Low‐Velocity Impact

ABSTRACT This paper constructed for the first time a finite element model of concave 3D angle‐interlock woven composites (3DAWCs) at the yarn scale, which can accurately simulate the stress, strain, and damage evolution of curved composites under the low‐velocity impact (LVI) at 60° and 90° impact angles. A viscoplastic user‐mater (VUMAT) subroutine was coded based on the 3D Hashin failure criterion and linear damage evolution, filling the gap of traditional models in oblique impact simulation. To verify the reliability of the numerical analysis, a LVI test was conducted by a self‐developed multi‐angle impact device. The damage morphology was characterized by 3D profilometer and CT scanning. Validation of the load, displacement, and energy between experiments and computation is performed, and the finite element analysis is conducted based on the observed mechanical properties and their reliability. Both the experimental and finite element results showed that the oblique impact causes severe damage to the surface binder yarns, while the normal impact results in uniform force on each layer of yarns, resulting in a smaller damage effect.