Life prediction for continuous fiber reinforced composites under stochastic fatigue loading based on the Critical Element Concept

The fatigue life simulation model described in this paper is based on the Critical Element Concept which allows life prediction for multiple layer laminates under multiaxial loading. This modeling philosophy combines the phenomena of stifmess reduction and residual strength degradation during cyclic fatigue loading in a physically sensible way. A stochastic time signal can be prepared for fatigue life simulation by the rainflow cycle counting method and the Haigh diagram where use is made of curves of constant cycles to failure. The described simulation software for life prediction allows the consideration of arbitrary load signals represented by forces, moments, moisture and temperature and includes several failure criteria, namely those of Hashin and Puck. For multiaxial stress states a comparison of fatigue life time prediction based on different failure criteria can be performed.