A Viscoelastic Cohesive Law for Rate and Temperature Dependent Mixed Mode Delamination

Abstract

Interlaminar failure of laminated composites is adequately described using bilinear/exponential cohesive zone modelling (CZM) simulations. However, state-of-the-art CZM formulations do not account for the environmental conditions that composite structures encounter in-service. Further enhancements of CZM models are required to account the effects of temperature and strain rate on the delamination behaviour. These effects could be modelled via fitting experimental trends, but such an approach would not provide a comprehensive explanation of the underlying physical mechanisms. In this work, a cohesive zone modelling framework that accounts the effect of loading rate and temperature on the interlaminar failure of laminated composites is presented. The loading and softening part of the traction-separation curve is represented by using the generalized Maxwell model, while the Zhurkov ’s kinetic theory of failure [1] is employed to describe progressive damage growth. The corresponding rheological elements introduced for a mixed mode-delamination are illustrated in Figure 1(a).