热-噪声载荷作用下薄壁结构非线性动态响应分析

Analysis of Nonlinear Dynamic Response of Thin-wall Structure Under Thermo-acoustic Loading

研究热噪声载荷作用下薄壁结构非线性动态响应特性,分析了薄壁结构热屈曲前后模态阵型及模态频率变化。进一步计算了热-噪声载荷联合作用下薄壁结构的横向位移响应,分析薄板中点位移概率密度,指出热屈曲板在强噪声载荷作用下,可围绕着两个平衡位置振动,发生跳变响应,且其响应频率随着声压级增大而增大。最后计算横向位移功率谱密度,研究结构几何非线性对结构刚度的影响,得出由于热及噪声对结构动态响应贡献不同,其共振频率及相应的功率谱密度发生规律性变化。

This paper inv Firstly, the mode shapes estigated the characteristics of structure dynamic response under thermal-acoustic loading. and modal frequencies before and after thermal buckled were analyzed. Then the thin-wall structure out-of-plane displacement response was evaluated, by analyzing displacement probability distribution func- tion（PDF）, it showed that thin wall panel vibrated around two different equilibrium configuration, that is snap- through motion, and also showed that snap-through frequencies increases with the increasing of sound pressure level （SPL）. Lastly, the displacement power spectrum density （PSD） is calculated to investigate the effect of geometric nonlinearity on structure stiffness. It shows that the resonant frequency and corresponding displacement PSD change with different thermal-acoustic contributions tO structure dynamic response.