中文摘要：

设备舱裙板支架作为连接设备舱底板和裙板的承载部件,在运用中承受来自裙板和底板的气动压力以及振动载荷,出现疲劳裂纹。开展支架裂纹断口的宏观分析,统计开裂支架的运用里程;基于高铁客运专线线路测试,得到明线运行、会车以及隧道运行、会车工况下设备舱裙板和底板的内、外侧气动压力以及压差值;对支架进行线路动应力测试,得到开裂部位的等效应力和一阶主频;采用脉冲激励法进行设备舱支架模块的模态试验,得到支架的垂向和横向一阶模态频率。研究结果表明,支架发生裂纹的主要成因是裙板、底板内外气动压力差产生的激励与支架自振频率具有交集,支架产生共振,共振现象使支架结构产生较高的应力幅值。该研究对确保高速列车运用安全以及为支架的新结构设计提供了参考。

英文摘要：

As the load bearing structure, the equipment cabin frames connecting the bottom plates and apron plates are acted on the aerodynamic load and vibration load, which appear the fatigue cracks in service. The crack macro analysis of the frame fracture section and the life mileage statistics of the frames are demonstrated. On the basis of the online pressure test of the equipment cabin on the passenger dedicated railway lines, the inside and outside aerodynamic pressure and differential pressure of the equipment cabin bottom plates and apron plates are executed and analyzed under the conditions of trains running or passing each other in the open air or in the tunnel. The equivalent stress and the first-order frequency of the crack position are gained by the on track dynamic stress test. The first-order modal frequency in the vertical and horizontal direction of the frames is tested using the pulse excitation method. The results show that the exciting frequency from the bottom plate or apron plate aerodynamic differential pressure is mixed with the frame natural frequency and the resonance of the frame happens, which induces the high dynamic stress amplitude. This idea is helpful to improve the equipment cabin frame design and ensure the high speed train running in safety.