Modelling mechanical performance of damaged laminates

Abstract

This article is the author’s contribution to the third World-Wide Failure Exercise which aims at benchmarking current damage models for composites. Reduction of thermo-elastic constants of laminates and their nonlinear behaviour due to intralaminar cracking and nonlinear shear response of the composite are analysed using global–local approach. The macroscopic properties of damaged laminates are expressed in simple forms containing density of intralaminar cracks and their surface displacement features obtained from local solutions. The initiation and evolution of the intralaminar damage is analysed using strength-based approach for laminates with thick layers and fracture mechanics approach for thin layers. Due to a lack of information, certain characteristics, such as statistical failure properties distribution parameters and transition point (thickness) from strength to fracture mechanics applicability, were assumed. All calculations are based on analytical expressions, some of which were developed previously through numerical analysis. The present method was applied to solve 9 out of the 13 test cases of the third World-Wide Failure Exercise and that was sufficient to illustrate the capability of the damage model.