关键词: 功能梯度材料板, 层合有限元模型, 热-噪声载荷, 动态响应分析, 非线性跳变, 仿真

Abstract:

In order to effectively analyze the nonlinear dynamic responses of aircraft and spacecraft functionally-graded-panel structures in thermal-acoustic environments, a new laminated modeling method of functionally graded material (FGM) panel is presented by using the composite multilayer shell elements. Based on this model, the dynamic response characteristics are researched under combined thermal-acoustic loading, and the effects of gradient index, temperature and sound pressure level (SPL) on the nonlinear dynamic responses are investigated. The new laminated modeling method avoids the shortcomings of the conventional finite element method (FEM) model which has to be divided into a large number of elements along the thickness direction. The implicit integration scheme avoids the strong experience requirement in the selection of participant modes and the loss of high-order modes information due to mode truncation by the mode superposition method. Simulation results show that the laminated modeling method is feasible and has good calculation accuracy. Unlike the anti-vibration performance of the ceramic-metal FGM panel whose thermal pre-buckling is somewhere between that of the ceramic panel and the metal panel, the thermal post-buckling can lead to a worst anti-vibration performance of the ceramic-metal FGM panel. The combination form of thermal buckling coefficient and sound pressure level is the key influence factor of snap-through response.

Key words: functionally-graded-material panel, laminated finite element model, thermal-acoustic loading, dynamic response analysis, nonlinear snap-through, simulation