摘要
为解决某型铁路货车120-1阀连接支管断裂问题,采用有限元仿真和线路试验相结合的方法确定断裂原因,进而提出改进方案并对其进行试验验证。通过分析断口特征和归纳失效规律,发现断口无明显塑性变形且失效数量与线路和支管吊座位置密切相关;有限元模态仿真表明原结构2(失效结构)的第一阶固有模态频率较低,且在断裂部位存在最大模态应变;线路试验对比发现,原结构2支管振动加速度RMS值分别为原结构1和改进结构的1.85、1.58倍,可安全运营里程仅为设计寿命里程的1/133;通过分析失效结构的响应特性,确定结构共振引发了支管疲劳断裂。改进结构可显著降低支管振动加速度和疲劳累积损伤,同时兼顾支管连接两端的疲劳强度,满足600万km安全运营要求。
In order to solve the fracture problem of the connecting branch pipe of 120-1 valve of a certain type of railway freight car;the method of combining finite element analysis and line test was used to determine the cause of the fracture;and then the improvement scheme was put forward and verified by test;Through the analysis of fracture characteristics and failure rules;it is found that the fracture of the branch pipe has no obvious plastic deformation and the number of failures is closely related to the location of the line and the hanger seat of the branch pipe;The finite element modal simulation shows that the first natural modal frequency of the original structure 2(failure structure)is low;and the maximum modal strain exists at the fracture site;The comparison of line tests shows that the acceleration RMS value of the original structure 2 is 1.85 and 1.58 times of that of the original structure 1 and the improved structure respectively;and its safe operating mileage is only 1/133 of the structural design life mileage;By analyzing the response characteristics of the failure structure;it is determined that the structural resonance causes the fatigue fracture of the branch pipe;The improved structure can significantly reduce the vibration acceleration and fatigue cumulative damage of the branch pipe while addressing the fatigue strength of both ends of the branch pipe connection;which can meet the requirements of 6 million km safe operation.
作者
姬程翔
孙守光
杨广雪
陈璨
JI Chengxiang;SUN Shouguang;YANG Guangxue;CHEN Can(School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China;Locomotive&Car Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2021年第3期77-84,共8页
Journal of the China Railway Society
基金
国家重点研究开发计划(2017YFB1201302-10A)
国家自然科学基金(11790281)。
关键词
铁路货车
制动系统
支管断裂
模态分析
振动疲劳
railway freight car
braking system
branch pipe fracture
modal analysis
vibration fatigue
作者简介
姬程翔(1993-),男,山东泰安人,博士研究生。E-mail:18116036@bjtu.edu.cn。
