Mode II- delamination modeling in multi-directional laminates using cohesive zone methodology under static and dynamic loading

Abstract

Most of the ply-by-ply laminated composite structures are constrained by delamination type of failure under different loadings. There were attempts to develop modeling methods for delamination under static and dynamic loads in the past. Most of the earlier attempts are focused on the unidirectional laminates because of complexity involved in the multi-directional laminates. However, in the real life, many time multi-directional laminates are used. This paper is an effort to create such modeling methodology for multi-directional carbon composite laminates (with 0–0, 45–45 and 90–90 interfaces) under static and dynamic loads. For modeling the static load case, Ansys software is used with the in-built contact based cohesive zone material model. The mode II experiments were conducted on multi-directional carbon composite coupons as per ASTM standards and the load displacement behavior is verified using the finite element analysis (FEA) cohesive zone models (CZM). Mode II test coupons are modeled in 3D, and the delamination is captured in the analysis simulation. For dynamic loading, LS-Dyna is used with the in-built tiebreak contact-Dycoss-Option 9 capabilities which are almost similar to the cohesive zone elements. The results indicate that cohesive zone models can predict the delamination in the kind of materials under static and dynamic loading conditions. The modeling methods will be further improvised for both situations to make it more robust and ready for applications to aircraft engine components in consideration of delamination.