基于Timoshenko梁求解钢轨导纳研究

利用有限元软件,建立钢轨导纳分析模型,采用完全法求解钢轨导纳,对Timoshenko梁与Euler梁模型计算结果进行对比研究。研究结果表明:在频率1 500 Hz以内,采用Timoshenko梁和Euler梁模型的钢轨位移导纳计算结果基本一致;当频率在1 500 Hz以上时,Timoshenko梁模型仍能较好反映导纳的峰—峰值变化规律;采用Timoshenko梁计算得到的前4个导纳峰值频率依次为450 Hz,700 Hz,1 000Hz和1 250 Hz,最大值发生在1 250 Hz,其中位移导纳最大幅值为4.19×10-8m/N;钢轨频响曲线的峰值与模态固有频率一一对应,通过对比认为,钢轨在1 250 Hz频率发生了Pinned-pinned振动。

Study on Solution of Rail Admittance Based on Timoshenko Beam Theory

The computation model of rail admittance was built with finite element soft.The rail admittance was obtained by Full Method.The computation result based on Timoshenko beam model was compared with the Euler beam model.The results show that,within 1 500 Hz frequency,the computation results of two models are basically identical.When the frequency is above 1 500 Hz,Timoshenko beam model can better reflect the peak-peak variation regular.The frequencies of the first four peak of rail admittance curve are 450 Hz,700 Hz,1 000 Hz,and 1 250 Hz.The maximum value of rail displacement admittance is 4.19×10-8 m/N.The peaks of frequency-response curve correspond with the rail ’s natural frequency.By contrast,the results show that Pinned-pinned vibration produced at 1 250 Hz.