Interfacial failures in a compressive shear strength test of glass/polymer laminates

Abstract

A computational method for interfacial failure modeling in composite material systems using cohesive elements is developed. This method is based on phenomenological cohesive zone models implemented within an implicit finite element framework as cohesive elements. Dynamic 2D and 3D cohesive elements have been developed and are used to simulate a compressive shear strength (CSS) test. The CSS test is employed in the polymer industry to measure polymer/substrate adhesion. The computational framework is first verified against existing analytical solutions for dynamic crack growth in double cantilever beam specimens. The phenomenon of stable crack growth followed by unstable crack growth observed in the CSS experiment is simulated. Various crack growth behaviors, obtained for different sizes of the initial pre-flaw along the interface, are studied. The phenomenon of dynamic crack “pop-in”, consisting of dynamic crack growth followed by crack arrest and stable crack growth, is investigated. The influence of the cohesive zone model parameters on crack “pop-in” as well as stability of crack growth are studied. A 3D dynamic simulation of a square plan form of CSS test is performed. The 3D analyses reveal the mixed-mode behavior in crack front growth along the interface and local “pop-through” of the crack front near the free edge of the CSS test specimen.