The Influence of Fiber/Matrix Debonding on Inelastic Micro-Mechanical Behavior of Cross-Ply IMC Composites

In this study the effect of stress field on delamination and fiber/matrix debonding in laminated composite panels is investigated from the micro-mechanical point of view by means of 3-D Finite Element Models. Specifically, the behavior of two-layer cross-ply symmetric laminates made up of SCS-6/Ti-24Al-11Nb Intermetallic Matrix Composite (IMC) during cooling from the processing temperature is studied. The results show that large plastic strains occur at the fiber/matrix interface at the fiber end on the laminate free edge which may eventually extend to the interface of the layers of the laminate inflicting delamination damage. This phenomenon is more serious at the corner areas of the laminate. It also can be shown that this situation is more serious for the four-layer laminate compared to the results of two-layer composite.