车体一阶垂向弯曲频率解析分析

Analytic Analysis of the First Order Vertical Bending Frequency of Carbodies

基于Timoshenko梁的振动理论,结合车体结构自身的特点,建立了车体结构一阶垂向弯曲频率的解析计算方法。通过引入截面有效剪切系数的概念,结合截面剪切形状系数,一起考虑车体闭合截面的剪切对固有频率的影响,引入车体垂向形心变异系数对一阶垂向弯曲频率解析式进行修正。利用有限元法和车体模态试验对该解析方法进行了验证。结果显示,车体一阶垂向弯曲频率解析值与有限元结果的误差为2.8%,与试验结果的误差为1.7%,车体垂向形心变异系数对一阶垂向弯曲频率影响最大。

On the basis of the vibration theory of Timoshenko beam,in combination of the carbody structure,the analytic calculation method for the first order vertical bending frequency of the carbody structure is set up.By introducing the concept of sectional efficient shearing coefficient,in combination of the sectional shearing shape coefficient,the effect of shearing of the closed section on the natural frequency is considered,and the first order vertical bending frequency analytic formula is rectified by introducing the vertical centroid variation coefficient of carbody.The finite element method and carbody modal test are used to verify the analytic method.The result shows that the error between the analytic value of the first order vertical bending frequency of the carbody and the finite element result is 2.8%,the error with the test result is 1.7%,and the effect of vertical centroid variation coefficient of the carbody on the first order vertical bending frequency is the maximum.