飞机蒙皮2A12铝合金搅拌摩擦焊的数值模拟研究

Numerical Simulation Study on Friction Stir Welding of Aircraft Skin 2A12 Aluminum Alloy

基于COMSOL对民航飞机蒙皮材料2A12铝合金搅拌摩擦焊进行了多物理场耦合的数值模拟研究,分析了焊接速度、搅拌头转速对模型中温度场及残余应力的影响,并通过实验对比验证了模型的准确性和可靠性。结果表明,在2A12铝合金板搭接部位,温度分布呈现"V"形分布。铝合金板中的最高温度及工件中的残余应力均随着焊接速度和搅拌头转速的变化而变化,为了保证焊接质量,最大焊接速度一般不能高于1.9 mm/s。同时,随着搅拌头转速的增加,工件中的最大残余应力和最高温度呈现先增大后逐渐平稳的趋势;纵向应力和横向应力分布均为M型,在焊缝处纵向应力集中为拉应力,横向应力在工件边缘表现为压应力,在焊缝附近为拉应力。

Based on COMSOL, the multi-physics coupling simulation of 2 A12 aluminum alloy friction stir welding of civil aircraft skin material was carried out. The effects of welding speed and stirring head rotational speed on temperature field and residual stress of the model were analyzed. The accuracy and reliability of the model were verified by experiment. The results show that the temperature distribution shows a "V" shape distribution at the lap joint of the 2 A12 aluminum alloy plate.The highest temperature in the aluminum alloy plate and the residual stress in the workpiece vary with the welding speed and the rotation speed of the mixing head. In order to ensure the welding quality, the maximum welding speed is generally not higher than 1.9 mm/s. At the same time, with the increase of the rotating speed of the stirring head, the maximum residual stress and the highest temperature in the workpiece firstly increase and then gradually stabilize. The longitudinal stress and the lateral stress distribution are M-type, and the longitudinal stress concentration at the weld is the tensile stress. The transverse stress acts as compressive stress at the edge of the workpiece and tensile stress near the weld.