Fatigue life prediction of composite laminates using a stress redistribution function

Within the framework of a statistical model and using the concept of a representative volume for damage evolution, a new way of determining the stress redistribution function to predict residual strength and fatigue life of a composite laminate was developed in terms of the fatigue behaviour of its laminae. The residual strength distribution function and the failure probability of composite laminates were derived. Knowing the degradation behaviour of residual strength for the property profile associated with the critical element, the static strength distribution and a stress redistribution function evaluated from the model of stiffness reduction of the composite laminate, the fatigue life of composite laminates can be determined from the failure probability. Comparison with experimental data for the glass/epoxy unidirectional, [±45,0]_2s and [±45,0]_2s laminates shows good agreements with the theoretical predicted values.