Fatigue life prediction of thin-walled structures subjected to combined thermal-acoustic loadings

The fatigue life of thin-walled metal structures under combined thermal-acoustic loadings is predicted based on critical plane model. The thermal loading could induce buckling and "snap through" type nonlinear vibrations of the structure, and makes it subject to large mean stresses. In order to take into account the effect of mean stresses induced by temperature loading, a new critical plane model based on shear strain is proposed. The model is first validated with experimental data under various strain paths, and then applied to predict the fatigue life of thin-walled metal structures under combined thermal-acoustic loadings. The result indicates that the thermal loading can significantly reduce the estimated fatigue life of the structure.