摘要
为直观了解钢轨砂带打磨后钢轨表面的残余应力状态,在磨削试验台上开展磨削工艺参数对残余应力影响的试验研究,采用便携式残余应力仪测量磨后轨面中线轨向残余应力。结果表明:打磨后轨面在磨削方向产生了拉伸残余应力,大小在100~300 MPa;而径向残余应力则主要以压应力形式存在,大小在0^-250 MPa。为研究残余应力形成过程中影响因素的作用机理,进行基于热力耦合的单磨粒划擦三维有限元仿真分析,揭示摩擦系数、切入深度和切削速度对钢轨表层残余应力分布的影响规律并分析其机理成因。最后,根据试验和仿真结果建议打磨列车的末端打磨单元采用开式打磨,砂带要求磨粒粒度小、自锐性强,磨削工艺优选低压、低速,并增设水介质冷却与润滑。
To intuitively understand the residual stress state on the rail surface after belt grinding,the influences of grinding parameters on residual stress were investigated on a test bench.Portable residual stress instrument was used to acquire the residual stress along the central line on the ground rail surface.The residual stress along the grinding direction was tensile,the value ranges from 100 MPa to 300 MPa,while the one along the radial direction was compressive,the value ranges from 0 to-250 MPa.To investigate the mechanisms of the influencing factors during the forming process of residual stress,a 3D finite element model(FEM)of single-grain scratching based on thermo-mechanical coupling method was developed.Effects of contact surface friction,cutting depth and cutting speed on residual stress distribution in rail sub-layer were revealed,respectively,The mechanism was also analyzed.Finally,according to the experiment and simulation results,it is suggested that the grinding unit at the end of the grinding train should adopt open grinding.The abrasive belt requires small particle and strong self-sharpening.The grinding process should be suggested using low grinding pressure and low grinding speed with water for cooling and lubrication.
作者
王文玺
李建勇
吴源
樊文刚
WANG Wenxi;LI Jianyong;WU Yuan;FAN Wengang(College of Mechanical Engineering, Chongqing University, Chongqing 400044, China;School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China;State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing 400044, China)
出处
《金刚石与磨料磨具工程》
CAS
北大核心
2020年第3期5-12,共8页
Diamond & Abrasives Engineering
基金
中央高校基本科研业务费项目(2019JBM050)。
关键词
钢轨磨削
砂带磨削
残余应力
有限元
划擦
rail grinding
belt grinding
residual stress
finite element model
scratching
