Chapter 9 - Viscoelastic cohesive/friction coupled model and explicit finite element analysis for delamination analysis of composite laminates under dynamic three-point bending

Abstract

This chapter develops a viscoelastic cohesive/friction coupled model is developed to predict the mixed-mode delamination of composite laminates under strain rate loading. Similar to Chapter 7, a continuous transition from the cohesive state to the frictional state is described by superimposing a variable tangential friction onto the regular tangential cohesive traction in the frictional sliding criterion. The regular cohesive traction comes from a modified Xu and Needleman's exponential cohesive model with continuous mathematical description at the peak cohesive traction and the viscous cohesive traction is taken as the hereditary integral representation of linear viscoelasticity. After the frictional sliding criterion is satisfied, the numerical algorithm for solving the tangential cohesive traction is developed. Then, the recursive algorithm for solving the incremental stress and strain of viscoelastic solids is developed. Explicit finite element analysis is performed on the single-leg bending (SLB) and the end notched flexure (ENF) composite laminates using ABAQUS-VUEL subroutine to solve the traction and separation.