4 结论

（1）主变压器风道的一阶垂向弯曲固有频率36.8HZ与该风道垂向加速度振动能量的主频37.9 Hz极为接近，风道底板产生共振并表现为弯曲振型。

（2）通过RADIOSS对风道进行谐响应分析，得到了主变压器风道底板的位移与应力。当风道共振时，风道应力被放大好多倍，应力值为134MPa，超出其材料的许用应力125MPa，易导致风道底板产生局部裂纹。

（3）通过改善主变压器风道的刚度分布，使风道的固有频率远离车体振动频率，避免了风道共振现象，提高了风道的寿命。

5 参考文献
[1] 廖炳荣.基于多体动力学和有限元法的机车车体结构疲劳仿真研究[D].成都:西南交通大学,2006：64-65.
[2] 李楚林,张胜兰等.HyperWorks分析应用实例[Ｍ].北京:机械工业出版社,2008：29-57.
[3] JIS E7106:2006，铁路机车车辆客车结构体设计一般要求[S].

The Harmonic Response Analysis of Main Transformer Air Duct
Sun Weiguang Tian Aiqin

Abstract：The mode and harmonic response analysis of main transformer air duct are obtained by using HyperWorks, by which the time response values of displacement and stress of main transformer air duct are obtained, the simulation data are consistent to test basically. The simulation analysis opens out the rootstock of fatigue crack of main transformer air duct owing to the biggish stress by the one step perpendicularity direction bend model of main transformer air duct. The stiffness distributing of main transformer air duct is ameliorated by simulation analysis, by which the one step perpendicularity direction bend model of main transformer air duct be apart from the perpendicularity direction acceleration vibration frequency of bodywork in order to avoid the resonance of air duct.

Key words：main transformer air duct；model shape；harmonic response