喷丸强化高速列车铸钢制动盘残余应力场有限元研究

Finite Element Study on Strengthening Residual Stress Field of Cast Steel Brake Disc of High-speed Train by Shot Peening

高速列车制动盘作为列车运行的安全保障,其耐磨性与疲劳寿命影响着列车的制动性能。为提高列车制动盘的耐磨性,延长疲劳寿命,建立了喷丸强化制动盘有限元模型,利用ANSYS/LS-DYNA有限元分析软件对喷丸强化的弹丸撞击角度、弹丸材料、弹丸直径、弹丸撞击速度及弹丸多层重复撞击多组工艺参数进行仿真模拟,分析喷丸强化之后残余应力分布图与残余应力场分布曲线。结果表明:在单弹丸条件下,弹丸喷射角度、弹丸材料密度、直径、速度与产生的总压应力层深度成正比。在多层弹丸条件下,增加反复冲击次数能有效降低残余拉应力和残余应力梯度,反复冲击一定次数后最大残余应力值增长减缓并最终趋于饱和。使用钢丸、弹丸直径为0.8 mm、弹丸速度为10 m/s、喷射角度为90°的工艺参数组合进行喷丸强化效果为佳,有限元分析结果可为喷丸强化高速列车铸钢制动盘选择合理的工艺参数提供依据。

High-speed train brake disc as a safety guarantee of train operation, its wear resistance and fatigue life affect the braking performance of the train. In order to improve the wear resistance of train brake disc and prolong the fatigue life, a finite element model of shot peening brake disc was established.The finite element analysis software ANSYS/LS-DYNA was used to simulate the impact angle of projectile, projectile material, projectile diameter, projectile impact velocity and multi-layer repeated impact of projectile. The residual stress distribution diagram and residual stress field distribution curve after shot peening were analyzed. The results show that under the condition of single projectile, projectile ejection angle, projectile material density, diameter and velocity are proportional to the total compressive stress layer produced. Under the condition of multi-layer projectile, increasing the number of repeated impacts can effectively reduce the residual tensile stress and residual stress gradient. After a certain number of repeated impacts, the increase of the maximum residual stress value slows down and finally tends to saturation. In this paper, the combination of process parameters including steel shot, projectile diameter of 0. 8 mm, projectile velocity of 10 m/s and injection angle of 90°are used to achieve the best shot peening effect. The finite element analysis results can provide a reasonable basis for the selection of process parameters for shot peening high-speed train cast steel brake disc.