Fatigue reliability evaluation for composite laminates via a direct numerical integration technique

direct numerical integration technique for evaluating fatigue reliability of composite laminates under varying stress amplitudes is presented. A number of cumulative damage models are adopted to construct the limit state equation for the laminates in the reliability analysis. Existing fatigue life distributions of composite laminates under cyclic stresses of constant amplitude are used in the reliability assessment of the composite laminates under varying stress amplitudes. The accuracy of the proposed method in fatigue reliability prediction is then verified by experimental fatigue life data of varying stress amplitudes. A comparison between the present method and the modified b-method is also made to illustrate the suitability of the present method in fatigue reliability prediction. 117 1998 Elsevier Science Ltd.