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为了有效地分析热-噪声联合载荷作用下的飞行器功能梯度壁板结构的非线性动态响应,提出了运用复合材料多层壳单元建立功能梯度材料(FGM)板的层合有限元建模新方法,研究了FGM板在热曲屈前、后状态下复杂的非线性时域动态响应特性,并探讨了梯度指数、热曲屈系数及声压级(SPL)等参数对FGM板非线性动态跳变响应的影响规律。FGM板三维层合建模新方法避免了采用常规有限元法(FEM)建模时需要在厚度方向划分大量单元的缺点;求解FGM板非线性动态响应时采用的隐式积分方案避免了模态叠加法对参与模态选择的经验性要求及模态截断造成的信息丢失等缺陷。仿真结果表明:FGM板层合有限元建模新方法合理可行、过程简便、计算精度高;研究发现:陶瓷-金属FGM板在热屈曲后的抗声振性能并不像热屈曲前那样介于金属板和陶瓷板之间,而是表现最差;热屈曲系数及声压级的组合形式是导致FGM板发生非线性跳变响应的主要影响因素。
In order to effectively analyze the nonlinear dynamic response of aircraft functional graded siding under thermal-noise combined loading, a new method of modeling laminated finite element (FEM) using functional multi-layer shell elements (FGM) , The complex nonlinear time-domain dynamic response characteristics of FGM plates before and after hot buckling were studied. The effects of gradient index, thermal buckling coefficient and sound pressure level (SPL) on the nonlinear dynamic jump Change the law of response. The new method of 3D laminating modeling of FGM plate avoids the disadvantage that a large number of cells need to be divided in the thickness direction when using the conventional finite element method (FEM). The implicit integration scheme used to solve the nonlinear dynamic response of the FGM plate avoids the modal The superposition method ’s empirical requirements for participating in modal selection and the loss of information caused by modal truncation. The simulation results show that the new method for modeling the laminated finite element of FGM plate is reasonable and feasible, the process is simple and the calculation accuracy is high. The results show that the anti-vibration performance of ceramic-metal FGM plate after thermal buckling is not as good as that before thermal buckling Metal plate and ceramic plate, but the worst performance. The combination of thermal buckling coefficient and sound pressure level is the main factor leading to nonlinear transition response of FGM plate.