以5A06铝合金焊接模拟件的一次焊接接头和二次焊接（补焊）接头为研究对象，通过拉伸试验、疲劳试验，以及对疲劳断口形貌观察，研究了补焊对该焊接接头力学性能的影响。结果表明：补焊会造成焊接接头力学性能的下降，其中静强度和中值疲劳强度下降明显；焊缝是接头拉伸强度与疲劳性能的薄弱部位，补焊会造成焊缝附近金属晶粒粗大。

With the initial welded joint and second (ropair welding) welded joint of the simulated welded part of 5A06 aluminum alloy as research objects, the influence of repair welding on the mechanical properties of the welded joint was studied by tensile test, fatigue test and fatigue fracture morphology observation. The results show that the repair welding decreased the mechanical properties of the welded joint, especially decreased the static strength and median fatigue strength significantly. The weld seam was the weak part of the welded joint in tensile strength and fatigue performance, and the repair welding gave rise to the coarse grains of the metal near weld seam.