Equivalent Spectral Method to Estimate the Fatigue Life of Composite Laminates Under Random Vibration Loadings

The power spectral density (PSD) of an equivalent stress is proposed to analyze the fatigue life of composite laminates under random vibration loadings using the Tsai–Hill criterion. The vibration fatigue life can be estimated based on the rainflow amplitude probability density function p(S) of the equivalent stress, which is obtained from this PSD, combined with the S-N curve of the materials. The fatigue life analysis of a random vibration fatigue experiment of composite laminates was carried out, and the calculation results were in accordance with experimental data, which indicates that the fatigue life analysis model proposed gives a satisfactory prediction accuracy.