Chapter 6 - Damage in composite materials – Overall approach

Abstract

The presentation in this chapter is based on the work of Voyiadjis and Kattan (2006). In this section the overall and local approaches to damage characterization in fiber-reinforced composite materials will be formulated. The formulation is both consistent and systematic. The final outcome will be to show that under similar assumptions both the local and overall approaches yield similar results when applied to fiber-reinforced metal matrix composites. This demonstration will be shown for the linear elastic case in this work. The fibers are assumed to be continuous and perfectly aligned. In addition, a perfect bond is assumed to exist at the matrix–fiber interface. A consistent mathematical formulation is used to show the equivalence of the two approaches in this case. The elastic stiffness matrices are derived using both approaches based on the damage variable and are shown to be identical in both cases.