边界条件对比例车体模态参数的影响  

Effect of Boundary Conditions to Modal Parameters of Proportion Body

作　　者：史艳民 缪炳荣[1] 李旭娟[1] 杨忠坤[1] 王名月[1] 

机构地区：[1]西南交通大学牵引动力国家重点实验室,四川成都610031

出　　处：《机车电传动》2017年第2期67-71,共5页Electric Drive for Locomotives

基　　金：国家自然科学基金项目(51375405);牵引动力国家重点实验室自主研究课题(2016TPL_T10)

摘　　要：边界条件是结构进行模态分析的基础,不同的边界条件施加方式通过改变结构刚度影响结构模态参数。首先通过理论推导计算模态分析和试验模态分析的基本原理,然后对比例车体有限元模型建立5种可行的边界约束条件,计算分析知弹簧悬挂时比例车体前30阶固有频率与自由模态最大误差为0.02346%,边界条件4和边界条件5时固有频率最大误差分别为25.3386%和10.2383%,在试验模态中可用弹性悬挂模拟结构自由模态。对弹簧悬挂、弹簧杆悬挂和空簧支撑3种不同边界条件下的比例车体进行锤击模态试验分析,得出第3阶垂弯频率最大误差分别为2.545%、2.961%和4.812%,均小于误差允许值5%;利用模态判定准则(MAC矩阵)判定试验模态中结构固有频率的相关性,验证了边界条件对比例车体模态参数的影响。Boundary conditions are foundation of structural modal analysis. Different boundary conditions loading methods influence structural modal parameters via changing the structural stiffness. By comparing the basic principles of computational modal analysis and experimental modal analysis through theoretical deduction, and establishing five kinds of feasible boundary conditions for proportion body finite element model, maximum error of elastic suspension of top 30 step modal parameters of proportion body compared to free mode was calculated to be 0.02346%, and the maximum error of boundary conditions 4 and 5 was 25.3386% and 10.2383%, respectively. Therefore, we could utilize elastic suspension simulated structure free mode in experimental modal. With analysis of hammering modal test for proportion body while three different boundary conditions respectively effecting （spring suspension, spring rod suspension and air spring support）, the maximum error of first 3 vertical bending frequencies was obtained to be 2.545%, 2.961% and 4.812%, respectively, less than the error tolerance（5%）. The correlation of natural frequency of structure in test mode was also obtained through mode assurance criterion（MAC matrix）, which demonstrated the effect of boundary conditions on the modal parameters of proportion body.

关 键 词：比例车体 计算模态分析 试验模态分析 边界条件 

分 类 号：U260.11[机械工程—车辆工程]