Coupled experimental and computational analysis of fracture path selection in PMMA blocks

Abstract

While developing experimental and computational tools for analyzing crack path selection and failure loci in adhesively bonded joints, we have initially applied these tools for studying crack paths in pre-notched monolithic blocks of polymethyl methacrylate (PMMA), a common material for conducting brittle fracture experiments. Specimen configurations similar to the compact tension specimen but of varying length/width ratios were used to explore the effect of the T-stress on destabilizing the crack from growing straight along its original direction. Asymmetric versions of this geometry were also used to determine the effect of imposed mode mixity on crack path selection. These test configurations provided useful data for checking the robustness of the computational software based on a meshless local Petrov-Galerkin formulation of the boundary-value problem. The PMMA was assumed to be linear elastic, homogeneous and isotropic. A crack was assumed to initiate when the maximum principal tensile stress reached a critical value and propagate in the direction of the eigenvector of this stress. Effects of the mode-mixity on the crack propagation have been studied. ©2010 Society for Experimental Mechanics Inc.