高速动车组制动横梁裂纹故障分析及改进措施

为解决高速动车组原设计结构的制动横梁裂纹故障,对故障发生位置及数量进行统计,并对裂纹断口进行宏观、微观分析,分析表明断口为应力导致的疲劳断裂。对原设计结构的制动横梁进行线路制动载荷识别并将结果应用于有限元仿真计算,结果表明原结构制动横梁支撑座管卡安装孔边缘处存在应力集中,在承受交变载荷下易产生疲劳裂纹。结合有限元强度仿真结果,提出制动横梁结构改进方案并进行强度计算和线路实测动应力,结果表明改进方案制动横梁结构应力水平较原方案明显降低,改进结构可满足高速动车组运用要求。

Crack Failure Analysis and Improvement Measures for Brake Beam of High-speed EMU

In order to solve the crack failure of the brake cross beam of original design structure of high-speed EMU,the location and number of the faults were statistically analyzed,followed by the macro and micro analysis of the crack fracture.The analysis shows that the fracture is fatigue fracture caused by stress.The results of line braking load identification of the brake cross beam of the original design structure were applied to the finite element simulation calculation.The results show that stress concentration exists at the edge of the installation hole of the brake cross beam support pipe clamp of the original structure,which may lead to fatigue cracks under the alternating load.Combined with the finite element strength simulation results,the improvement scheme of brake beam structure was put forward,and the strength calculation and line dynamic stress measurement were carried out.The results show that the stress level of the brake beam structure of the improved scheme is significantly lower than that of the original scheme,and the improved structure can meet the application requirements of high-speed EMU.