复杂轴承支撑结构动力学特性的有限元方法研究

复杂轴承支撑结构由多个子结构组合而成,从而形成多个接触面.研究表明,这些接触面的存在对结构的动力学特性有着显著地影响,其对振动信号的衰减与反射是振动信号提取过程中的一个难题.针对这个问题,建立轴承支撑结构的有限元模型,利用Ansys Workbench对结构进行模态计算和传递函数的计算,采用与整体结构对比研究的方法,考虑螺栓预紧力的变化对结构振动特性的影响,分析结构受冲击载荷激励时响应的特点.结果表明,随预紧力的增大,各阶模态呈增大趋势,螺栓结构对高频信号的衰减作用更加明显,轴承故障信号在复杂传递路径中难以有效的传递.

Research on dynamic characteristics of the complicted bearing support structures by finite element method

Complicted bearing support structures are composed of several substructures, which forming the interface. Study shows that these interfaces have a significant influence on the dynamic characteristics of the system, the damping and reflection of the vibration signal due to the interface is a big problem in the process of signal extraction. Aiming at solving this problem, a finite element model of the bearing support structure is established. By using Ansys Workbench, the modals and transfer function of the model are calculated. Using the method of comparative study with the whole structure and the impact of the change of bolt pre-tightenning force is considered. The characteristics of the response when subjected to shock loading are analyzed. The results show that with the increase of pre-tightenning force, the modals increase, the attenuation of high frequency signal is more obvious and the bearing fault signal is difficult to be transmitted in the complex transmission path.