Analysis of the gradual failure process

Abstract

Inter Fiber Fracture is sometimes regarded as final fracture and in other cases as tolerable damage of the laminate. If IFF is regarded as tolerable, a “post IFF-analysis” of the laminate is necessary which comprises as an iterative process strain and stress analysis with elastic properties which are truly characteristic for the damaged laminate. This post IFF-analysis is understood here as “Gradual Failure Analysis”. The different approaches for the gradual failure analysis (fracture mechanics, damage mechanics and phenomenological models) are discussed briefly at the beginning of the chapter. Puck’s degradation models are then presented in more detail. Finally the implementation of Puck’s theory in a software code is described in detail.