Residual Strength Degradation Model and Theory of Periodic Proof Tests for Graphite/Epoxy Laminates*

Abstract

A fatigue residual strength degradation model has been derived based on the assumption that the residual strength decreases monotonically. The model is verified experimentally by use of Gr/E unnotched laminates under constant amplitude fatigue. The theory of periodic proof tests and reli ability prediction for composites have been established. Experimental data for specimens under periodic proof tests and fatigue loading have been generated. It is shown that the correlation between the experimental results and the theory of periodic proof tests is outstanding.