Progressive damage analysis of Open-Hole Compression based on a delamination-dependent bending-fracture model for fibre kinking and the Floating Node Method

Abstract

Compressive failure mechanisms of fiber reinforced polymers represent a significant challenge when accurately modeling common industrial problems. This thesis aims to deliver a physically representative computational framework capable of simulating Open Hole Compression. A novel approach, the Floating Node Method is adopted for modeling discontinuities. Furthermore, a constitutive law for fiber kinking, incorporating the microscale bending stress of a fiber under the assumptions of the Euler-Bernoulli beam theory, is proposed. This meso-scale Continuum Damage Model poses three requirements for kinking onset: 1) local failure of the matrix in the kink band; 2) fibers fracture due to bending; 3) the longitudinal compressive stress is sufficiently large to satisfy the previous requirement when the kink plane shear stresses is smaller than the traverse shear strength of the ply. The model is validated against experiments of different sized [45/90/-45/0]s laminates. The predicted panel strengths match experiments by less than 8%.