Nonlinear Response and Fatigue Life of Thin Plates Subjected to Non-Uniform Temperature Distributions and Acoustic Excitations

Abstract

A finite element formulation is presented for the prediction of nonlinear response of thin plates under a steady-state non-uniform temperature change over the thin plate and band limited Gaussian white noise. Thermal buckling temperatures and thermal deflections are obtained to explain the stability of panels, and modal frequencies of thermally buckled plate are obtained to explain the stiffness characteristics of panels. The stress responses of panels under thermo-acoustic loadings exhibit complex nonlinear characteristics. Miner linear accumulation damage theory and improved Rainflow counting cycle method are used for estimation of fatigue life of panels under combined thermo-acoustic loadings. Results show that the fatigue life decreases till the end of snap-through and then gives a rise trend. Afterward, the fatigue life reaches a steady state at low peak temperature area. As the peak temperature goes up sequentially, the fatigue life rises suddenly, and then reaches a steady state at high peak temperature area.