动车水箱疲劳振动试验及数值模拟研究-《郑州大学学报(工学版)》

文章信息/Info

Title:: Study on Vibration Fatigue Test and Numerical Simulation of EMU Tank

Author(s):: Wang Jianming; Li Xiaoxiao; School of Mechanical Engineering, Shandong University

Keywords:: weld fatigue life; Nominal stress method; vibration test; SN curve; Numerical Simulation

摘要:: 轨道车辆及车载设备大量使用焊接结构，其在振动载荷作用下的疲劳破坏通常发生在焊缝处。针对动车水箱焊缝疲劳寿命开展随机振动台架试验及数值仿真研究。在台架试验中，按试验规范输入强化加速度随机振动自功率谱，检验该水箱是否满足疲劳寿命的要求.在进行数值模拟研究中，按试验工况条件建立水箱疲劳寿命仿真模型，其中将振动试验的激振信号作为仿真的输入载荷，采用壳单元建立水箱构件及焊缝的有限元模型，通过附加质量等效内部液体，根据BS7608标准确定相应焊缝的S-N曲线，采用名义应力法预测水箱焊缝在试验工况下的疲劳寿命.仿真所得焊缝失效部位及疲劳寿命与振动台架试验结果基本吻合，说明该焊缝疲劳寿命预测方法的正确性，为焊接结构疲劳设计提供有效的分析算法。

Abstract:: Welded structures were commonly used for railway vehicles and equipment. Fatigue failure of welded structures with fluctuating loads usually occursed at weld seams. So Random Vibration Bench Test and Numerical Simulation for Fatigue Life of Welded EMU Tank were studied. Through the bench test, the acceleration power spectrum of the structure was input, simulating the random vibration of water tank fatigue conditions to get the tank vibration time domain signal. It was regarded as a fatigue simulation of the input load. The finite element model of tank and weld was established by shell element, and the internal liquid was equivalent by the additional mass method. According to BS7608 standard, different weld grade S-N curves were selected, prediction of fatigue life of water tank is based on nominal stress approach under test conditions. The simulation results show that fatigue failure site and fatigue life of weld in tank was similar to those that in the experimental tests of random vibration. This research proved the correctness of the fatigue life prediction method of weld, and could provide a theoretical reference for the fatigue design of the welded structures for EMU tank.