搅拌摩擦焊焊缝塑性金属流场的数值模拟

Simulation of Plastic Metal Flow Field in Friction Stir Welding

依据流体力学理论,建立搅拌摩擦焊的三维流场有限元模型,根据试验参数确定流场的定解条件对搅拌摩擦焊过程进行数值模拟,得到了焊缝塑性金属的三维速度场、流线轨迹。结果表明：焊缝上部金属呈规则的层流,下部金属呈不规则的紊流;塑性金属在厚度方向上发生了循环迁移,搅拌针附近的塑性金属沿搅拌针向上迁移,其外围的金属则向下迁移。

According to hydrodynamic theory,a finite element model of the three dimensional flow field for plastic metal was established,the three dimensional velocity and flow line trajectory of plastic metal were obtained by numerical simulation.The results show that,the upper welding metal is laminar flow and the lower metal is turbulent flow.The plastic metal around pin moves,upwards,its peripheral metal moves downwards.