铝合金搭接搅拌摩擦焊接头拉伸变形的数值模拟

Numerical simulation of tensile deformation on aluminum alloy FSW lap joints

摘要: 通过对2A12铝合金搭接搅拌摩擦焊接头的强度试验,研究了搭接搅拌摩擦焊接头的断裂行为,应用有限元方法对2A12铝合金板材搭接搅拌摩擦焊接头的拉伸力学响应进行了模拟计算,获得了搭接搅拌摩擦焊接头在外载作用下的局部应力应变分布与变形规律.结果表明,在搭接接头的搭接面上存在两个类裂纹的未焊接区域,塑性变形首先在搭接界面裂纹尖端区域发生,上板受拉侧裂纹尖端周围区域的塑性变形最大,是导致搭接搅拌摩擦焊接头上板的前进侧热影响区断裂的主要原因。

Abstract: Fracture behaviour of friction stir welded lap joints in 2A12 aluminum alloy was investigated by strength test.The distribution of stress and strain around the crack tip was calculated by finite element method under stretching forces.Analysis results show that plastic deformation occurs first at crack tip and the maximum plastic deformation is found in crack tip region in upper plate which lead to the fracture of heat-affected zone in upper plate.