An interface thick level set model for simulating delamination in composites

Abstract

SummaryThis paper presents a discontinuous thick level set model for modeling delamination initiation and propagation in composites. Interface elements are widely applied in delamination models to define a discontinuity between layers of a laminate. In this paper, the common damage definition in the constitutive relation of interface elements is replaced with a new definition developed using the thick level set approach. Following this approach, a band of damage with predefined length is considered where the damage is defined as a function of distance to the damage front. The specifications of suitable damage functions for the developed method are investigated, and an efficient damage function is introduced. A sensitivity analysis of numerical input parameters is performed, which proves that the model is not sensitive to the length of the damage band. Because the required element size is linked to the length of the damage band, the insensitivity to this length provides freedom to use coarser meshes. Furthermore, the model provides a direct link between fracture mechanics and damage mechanics, which enables further development of the model for fatigue analysis. Validation of this model is presented by conducting three‐dimensional mode I, mode II, and mixed‐mode simulations and comparing the results with analytical solutions. Copyright © 2016 John Wiley & Sons, Ltd.