基于有限元仿真的喷丸工艺参数对冲击坑形状和尺寸的影响

Impaction of Shot Peening Process Parameters to Dent Shape and Dent Size by Dynamic Finite Element Analysis

喷丸工艺是一种有效提高工件疲劳寿命和改善工件表面完整性的表面处理方法,被广泛应用于航空、航天、船舶、汽车等军民用领域。研究表明,弹丸冲击金属材料表面形成的冲击坑形状和尺寸与工件表面完整性有重要的对应关系,表面完整性是影响结构零部件工作质量、寿命和可靠性的重要因素。本文应用有限元分析的方法系统地研究了喷丸处理过程中的一些关键参数对形成的冲击坑形状和尺寸的影响,结果显示,弹丸速度、直径、材料、重复冲击次数对冲击坑的尺寸影响显著,同时,弹丸的屈服应力对冲击坑的形状影响显著,而弹丸与靶材之间的摩擦系数对冲击坑的形状和尺寸影响都较小。冲击坑直径比的饱和值为2.5,冲击坑深度比的饱和值为0.2。将冲击坑模拟结果与Nobuyuki等人用ANSYS软件所模拟的结果进行对比,结果吻合得较好。本文有限元模拟的结果,可用于对生产实际中喷丸工艺参数的优化,对新机研制中的飞机壁板等零件的喷丸成形工艺制定具有重要的指导意义。

Shot peening is an effective surface treatment technology to significantly improve fatigue life and surface integrality of the peened part and it is widely used in aerospace industry, ship building, car manufacture and other areas. Dent shape and size produced by single shot impacting on surfaces of a metallic component are closely related with surface integrity according the research. Surface integrity is an important factor which will affect the quality, performance, life and reliability of the parts and components. The variation of the dent shape and dent size versus shot parameter was systematically researched by proposing a finite element model for shot peening. Results show that velocity, diameter, material and repeating times of a shot all play important roles on the dent shape and size; the yield stress of the shot obviously affect the dent shape; and the friction coefficient between shot and target have little impact on the dent shape and dent size. The diameter ratio （diameter of pilled-up area /diameter of dent） reaches the saturated value of 2. S, and the depth ratio （piled-up height depth of dent） reaches 0.2. This result agreed well with the published numerical study of Nobuyuki Hirai et al. which was obtained using ANASYS computer program. The simulation results can be applied to optimize technical parameters for practical production, and to guide the process of shot peening forming of the aircraft panel.