Determining cohesive parameters in an n-segment constitutive law of interfaces through DCB tests

Abstract

R-curve behavior usually presents in the delamination growth process of composite laminates, which is mainly results by fiber bridging. To simulate the delamination with R-curve behavior, cohesive zone model with an n-segment constitutive law has been proposed. However, there are many parameters in the constitutive law and it is usually difficult to determine their values. To solve this problem, this study proposes a simple and efficient approach for the determination of an n-segment constitutive law. The determined constitutive law has been implemented in the ABAQUS software, using a user-defined subroutine. Three case studies with different material systems are performed to verify the wide applicability of the proposed approach. Good agreements between experimental and predicted load–displacement responses indicate the robustness of the proposed methodology. Only experimentally recorded load and displacement data are required in this method. This approach has the advantage of being easy to use and no need for parameter adjustment, which makes it convenient for determining any n-segment constitutive law and suitable for practical application.