Numerical analysis of the impact behaviour of a composite eco-structure

Abstract

An explicit numerical model is developed for the impact behaviour of a new composite eco-structure made of a plywood core and flax/epoxy composite skin. A constitutive orthotropic material behaviour is imposed to model the elastic response of plies of plywood core and flax skin. A stress-based modified Hashin-3D damage model with four independent failure criteria in tensile and compressive mode is incorporated for predicting the damage initiation. A strain threshold based exponential method is adopted to predict the damage scaling and its evolution. The above proposed model is implemented through user material subroutine (VUMAT) in ABAQUS Explicit. The developed model is validated with experimental low-velocity impact test results and can accurately predict the stiffness degradation, plateau, and post-peak softening of wooden plies. A good agreement with the better accuracy is achieved between the predictions and the test results.