基于光束离散的激光相变硬化蠕墨铸铁应力场数值模拟  

Numerical Simulation of Stress Field of Laser Phase Transformation Hardening Vermicular Graphite Cast Iron Based on Beam Discretization

作　　者：庞铭 谭雯丹 Pang Ming;Tan Wendan(Airport College,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学机场学院

出　　处：《激光与光电子学进展》2019年第23期191-197,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(U1633111,51206179);内蒙古自然科学基金(2017MS0540);中央高校基本科研业务费资助项目(201911);中央高校基本科研业务费项目中国民航大学专项(3122018D020);中国民航大学蓝天青年科研资金资助

摘　　要：为了研究基于光束离散的激光相变硬化蠕墨铸铁RuT300材料的应力分布状态,构建了离散激光相变硬化RuT300弹塑性本构模型,分析温度对热应力和残余应力的影响。结果表明:材料表面较大的热压应力分布与二维离散点阵光斑相对应,激光快速加热引起的材料各部分温度差异使得模型X轴路径上的热应力呈波浪形分布,离散光斑加载区域的X、Y方向热应力峰值为-635MPa,约为Z方向的1.8倍,随着深度的增加,模型截面热应力逐渐降低;材料表面激光加载区域的残余应力大于非加载区域,X、Y方向的残余拉应力为主要残余应力,应力值在200MPa左右,X轴路径上X方向的残余应力最大;随着激光功率的增加,残余应力峰值增大,材料受较大残余应力影响的区域扩大,延长激光加热时间时,加载区域残余应力峰值的变化幅度在2.4MPa内。Herein,the stress distribution state of laser phase transformation hardening vermicular graphite cast iron RuT300 is studied based on beam discretization using a constructed elastic-plastic constitutive model of the discrete laser phase transformation hardening RuT300.Additionally,the model considers the effect of temperature on thermal stress and residual stress.The results demonstrate that the large thermal stress on the material′s surface corresponds to a two-dimensional discrete lattice spot.Since rapid laser heating causes each part of the material to experience a different temperature,the thermal stress distribution is wavy along the X-axis path of the model.The maximum thermal stress in the Xand Y directions of the discrete spot loading region is found to be-635 MPa,which is 1.8 times that found in the Zdirection.In each section of the model,the thermal stress decreases gradually with an increase in the depth;the residual stress value in the laser loading region on the surface of the material is larger than that in the nonloading region.The residual tensile stresses in the X and Y directions of the model constitute the primary residual stress,with a value of approximately 200 MPa.The residual stress in the Xdirection along the X-axis path is the largest among the three directions.As the laser power increases,the peak residual stress value increases,and the area of the material affected by large residual stresses increases.However,when the laser heating time is prolonged,the change in the peak residual stress value in the loading region is within the range of 2.4 MPa.

关 键 词：激光技术 光束离散 相变硬化 应力场 蠕墨铸铁 数值模拟 

分 类 号：TG156.33[金属学及工艺—热处理]