INTERLAMINAR INTERFACE MODELING FOR THE PREDICTION OF DELAMINATION

Delamination is a phenomenon which involves complex degradations of layers and interlaminar connections. In order to take these degradations into account, a laminate is modelled as a stacking sequence of homogeneous layers and interlaminar interfaces. The aim of this article is to focus on the interface modelling and first identification. The interface is a three-dimensional medium the thickness of which is negligible compared to the in-plane dimensions. Therefore it can be modelled as a two-dimensional entity which ensures displacement and traction transfer from one ply to another. The interface depends on the angle between the fibre directions of two adjacent layers. In the first instance it is assumed to be elastic and damageable. The main interest of this model is that, using only a few intrinsic characteristics of the interface, it is possible to predict the tendency of a structure to delaminate. One of the main difficulties is to identify these characteristics. This approach allows a clear connection between fracture mechanics and damage mechanics. This modelling has been used for the predicting of delamination initiation and growth in the case of static loadings without buckling.