Evaluation of Composite DCB Delamination Growth by Combining Experimental Data and Numerical Analysis

Abstract

A study of quasi-static mode I delamination in a laminated unidirectional composite double cantilever beam (DCB) configuration was conducted experimentally and numerically. A two-dimensional (2D) finite element (FE) correction method that consisted of a series of analyses of the DCB compliances at different delamination lengths was conducted to establish an analytical correlation between the delamination length and the DCB opening compliance. This analytical correlation was then used to determine the delamination length provided the experimentally measured compliance. Consequently, the problematic delamination lengths generated from in-situ optical measurement were evaluated and corrected. Also, the fracture resistance curve was updated using the corrected delamination lengths. Good agreement in the loaddisplacement variation was then obtained between the experimental results and the subsequent 2D DCB FE modelling results using cohesive elements. Commentaries on the DCB quasi-static failure analysis and modelling using the cohesive zone modelling technique and the virtual crack closure technique were also provided.