噪声激励下典型复合材料铆接结构的声固耦合分析

针对CVI工艺下复合材料典型铆接板,提出一种适合复杂模型动力学分析的建模方法:采用Bush和RBE2的组合单元模拟铆钉连接,将板间的弱非线性接触力转化为接触刚度,建立该复合材料铆接板的有限元模型。同时,基于有限元-间接边界元法推导了考虑接触力的声固耦合动力学方程,开展了该复合材料铆接板在随机噪声激励下的声固耦合分析,并探讨界面接触对声固耦合系统固有特性和动响应的影响。研究结果表明,界面接触模型比界面刚接模型更为准确;刚接模型会增大复合材料铆接板连接界面的局部刚度,使得结构的固有频率偏高,响应峰值向高频处移动;考虑接触对结构的加速度响应影响较大,对应力响应影响较小。

Structure-acoustic coupling analysis of a typical composite jointed structure under noise excitation

Focusing on a typical composite jointed panel in the CVI technology,a finite element model was built in which the riveted joints were simulated by the combined elements of Bush and RBE2 elements,the nonlinear contact forces were transformed to contact stiffness;Utilizing the equivalent linearization method,the equation of motion of the structural-acoustic coupling system was formulated by the FEM-IBEM approach.Structural-acoustic coupling analysis under noise excitation was further conducted and the influence of interfacial contacts on the natural characteristic and dynamic response of this structural-acoustic coupling system was discussed.Results show that the interfacial contact model of the joints is more accurate than the rigid model.The rigid model increases the local interfacial stiffness of the composite jointed panel which will further lead to the increase of the system's nature frequencies.The peaks in frequency domain of the dynamic response of the system with rigid models tend to move towards the higher frequency domain.Interfacial contact has significant influence on structural acceleration but weak effect on stress.