Cumulative damage theory for composite materials: Residual life and residual strength methods

Abstract The cumulative damage problem is formulated in terms of a damage function which must satisfy certain conditions. It is shown that such a damage function can be used with residual life theory as well as with residual strength theory, and that these two approaches are equivalent. Various assumptions regarding the dependence of the damage function on fatigue variables lead to both known and new results of life prediction. Comparison of analytical results with available test data did not reveal a best fit of any one prediction to the data.