多轴载荷下车轮辐板裂纹扩展特性研究  

RESEARCH ON CRACK PROPAGATION CHARACTERISTIC OF RAILWAY WHEEL WITH WEB PLAT UNDER MULTIAXIAL LOADING

作　　者：周素霞[1] 肖楠[1] 谢基龙[1] 

机构地区：[1]北京交通大学轨道车辆结构可靠性与运用检测技术教育部工程研究中心,北京100044

出　　处：《工程力学》2010年第1期41-46,共6页Engineering Mechanics

基　　金：国家重点基础研究发展计划973项目(2007CB714705)

摘　　要：针对车轮在运行过程中的典型运用工况,采用有限元方法数值模拟了不同运用条件下车轮的机械应力分布,选取辐板最高应力部位作为裂纹的萌生位置。根据线弹性断裂力学理论研究了辐板裂纹在二轴载荷下的应力强度因子和T应力,最后结合Paris疲劳裂纹扩展方程及裂纹扩展门槛值,得到了二轴载荷下辐板表面裂纹的扩展特性和规律。从而得出了二轴载荷条件对辐板表面裂纹扩展的影响。分析结果表明:典型工况下,车轮辐板外侧处于受压状态,内侧处于受拉状态而且变化幅值较大。车轮辐板的内外表面的应力不同,使得辐板同时承受了弯矩,并且弯矩的周向分量和径向分量近乎于正比。由于T应力的影响,车轮辐板裂纹扩展速度比不考虑此应力时的值较为偏低。分析结果对预防车轮疲劳失效、优化车轮设计、保障行车安全,具有重要意义。Based on the typical service loads of railway wheel, the paper simulated the mechanical stress distribution under different service loads using finite element method. According to the linear elastic fracture mechanics theory, the stress intensity factor and T stress were also studied. At last, According to Paris fatigue crack propagation equation and the corresponding crack propagation threshold, the crack propagation characteristics and laws at the web plate under biaxial loads were obtained. The result showed that the crack propagation in the web plate was a typical fatigue damage. Under typical loads, the outside surface of the wheel is in compression and the inside surface is in tension. Inside and outside stresses at the web plat leds to the bending loading. Moreover, the circumferential components are proportional to the radial ones. The crack propagation rate is decreased due to the T stress.

关 键 词：车轮 有限元方法 多轴载荷 疲劳裂纹扩展 断裂力学 应力强度因子 

分 类 号：U270.33[机械工程—车辆工程]