1、Inherent dynamic characteristics analysis of heavy-load depressed-center flat frame based on substructure method关于以子结构法为基础的大底架的固有动态特性分析On the basis of the FE analysis the effects of vibration modes and selected modal numbers of the flexible depressed-center flat frame on dynamic responses of the veh
2、icle system are studied. The dynamic equation of the depressed-center flat frame has been derived. And its dynamic equation on modal coordinates, which can be transformed to physical coordinates, has also been established after super-elements are introduced. On the basis of the modal analysis theory
3、 the needed modal shapes and parameters of the frame can be solved. According to the structural features, position and connection status of the depressed-center flat frame, its FE model has been set up, and its inherent dynamic characteristics have been calculated. After the FE model of the depresse
4、d-center flat frame has been reduced by the substructure method, its elastic model including dynamic characteristics has been established. This method has greatly reduced the total number of DOF of the depressed-center flat frame to fit correct and effective analysis of vibration responses of the ve
5、hicle system. By studying the effect of modal number selection of the elastic body on the dynamic responses of the vehicle system, it is found appropriate to select the former eight orders of modal shapes, which facilitate sufficient calculation accuracy.摘要：在有限元分析的基础上，对车辆系统动态响应的挠性重载底架的振动模式和所选模型数据进行了研究。大底架的动态方程式得到了推理。在导入超单元后，建立出其模型坐标的动态方程式，也就是物理坐标。基于模型分析理论，底架的所需模型形状和参数能够解决。基于大底架的结构特点、位置和连接状态，建立其有限元模型，其固有动态特性在运算。大底架的有限元模型被子结构法减少之后，其弹性模型包括动态特性已建立。这种方法大大减少了大底架自由度的总数量，从而最适于车辆系统振动响应的正确性与有效性的分析。基于对车辆系统动态响应弹性体的模型数据筛选效果的研究，已找出了适合的前八种动态振型，促进满足运算精确性。
