基于子结构法的重载凹底平车底架的固有动态特征分析  

Inherent Dynamic Characteristics Analysis of Heavy-load Depressedcenter Flat Frame Based on Substructure Method

作　　者：周素霞[1] 谢云叶[2] 谢基龙[3] 张俊清[3] 

机构地区：[1]北京建筑工程学院机电与汽车工程学院,北京100044 [2]济宁职业技术学院汽车工程系,山东济宁272037 [3]北京交通大学轨道车辆结构可靠性与运用检测技术教育部工程研究中心,北京100044

出　　处：《铁道学报》2011年第8期28-32,共5页Journal of the China Railway Society

摘　　要：基于有限元分析,本文研究重载凹底平车底架弹性体的振动模态以及模态阶数的选取对车辆系统动态响应的影响。通过引入超单元,建立弹性体在模态坐标上的动力学方程,经过坐标变换得到物理坐标系上的方程;建立凹底架的有限元分析模型,计算分析其固有动态特征;同时,采用子结构法缩减处理凹底架有限元模型,建立有动态特征的凹底架弹性体模型,使描述凹底架的自由度总数减少,同时也保证计算的精度。对凹底架子结构超单元模型,计算分析振动模态,并与其有限元模型的模态结果进行比较。结果表明:子结构法的计算精度高,能满足车辆系统结构振动响应分析的要求。通过计算凹底架模态阶数对车辆系统动态响应的影响,得出选取凹底架的前8阶模态是合适的,有足够高的计算精度。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 vehicle 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 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 depressed-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 vehicle 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 calarlation accuracy.

关 键 词：子结构法 重载 多体系统动力学 有限元 

分 类 号：U270.1[机械工程—车辆工程] O235[交通运输工程—载运工具运用工程]