Aerodynamic Load and Fatigue Damage Law of EMU Equipment Cabin under Typical Working Conditions
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摘要: 京广高铁武广段运用的CRH-3C型高速动车组设备舱内支架、裙板吊挂等焊缝位置以及其它应力集中点常有疲劳裂纹出现,而该现象在京津城际上运用的同型号动车组中却比较罕见。针对这种现象,考虑是武广段大量的隧道群所致。为了对此进行验证,在某动车组设备舱内裙、底板布置了大量气压和应变传感器,在沪昆高铁南昌西-宜春段进行了不同速度下大量的隧道通过、交会等典型工况测试,获得了丰富的气动载荷和动应力数据。以此试验为基础,对若干工况下,关键位置气动载荷和动应力的变化规律进行研究发现,伴随气压幅值突变,大多位置应力水平均有提高,裙板中央以及靠近车头的前部底板等处尤为明显。上述结论对武广段的CRH-3C型动车组设备舱疲劳破坏现象给出了合理解释,并对今后基于不同线路特点,有针对性的动车组型号选择和设备舱结构的优化设计提供了建议。Abstract: The CRH-3C high-speed EMU running on the Wuhan-Guangzhou section of the Beijing-Guangzhou high-speed railway has been found fatigue cracks in the frame, elevator of skirt plate and other stress concentration points of equipment cabin. But this phenomenon is seldom found in same type EMUs running on the Beijing-Tianjin intercity high-speed railway. The reason is considered to be caused by a large number of tunnel groups in the Wuhan-Guangzhou section. In order to verify this idea, a group of air pressure and strain sensors were mounted in the skirt plate and bottom plate of an EMU equipment cabin. The EMU train was tested in the Nanchang West-Yichun section of the Shanghai-Kunming high-speed railway to acquire aerodynamic load and dynamic stress data under typical conditions, including tunnel driving and meeting zones, etc. According to this test, the variation of aerodynamic loads and dynamic stresses at key positions under several working conditions were analyzed. The results show that there often occurs sudden change of the air pressure amplitude while entering a tunnel or meeting in a tunnel and result in increased stress level of most positions, especially in the center of skirt plate and the bottom plate near the front. The analysis result gives a reasonable explanation for the fatigue failure phenomenon of CRH-3C EMU equipment cabin in Wuhan-Guangzhou section, as well as provides suggestions for the selection of EMU models based on different railway characteristics, and optimization design of equipment cabin structure.
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Key words:
- EMU /
- experiments /
- working conditions /
- aerodynamic loads /
- stresses /
- fatigue damage
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表 1 部分设备舱构件裂纹数目统计
名称 裙板 支架 裙板吊卡 合计 京津线 96 31 12 139 武广线 438 175 141 754 表 2 典型工况下应力测点等效应力幅
MPa 测点 明线运行 明线交会 进入隧道 隧内交会 9 48.44 67.54 98.30 106.29 10 37.07 42.39 74.25 53.87 11 19.81 20.37 28.46 33.53 12 62.06 69.98 131.15 101.77 13 21.20 35.63 54.24 44.43 14 15.92 19.61 31.72 30.03 15 32.13 31.72 47.13 61.74 均值 33.80 41.03 66.46 61.67 表 3 不同区段的等效应力幅值
MPa 测点 无隧道区段应力 隧道区段应力 9 53.52 72.94 10 40.03 56.43 11 25.81 37.71 12 56.69 84.14 13 21.37 29.88 14 27.82 24.15 15 39.67 38.11 均值 37.84 49.05 -
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