铝合金搅拌摩擦焊物理场三维数值模拟

3D numerical simulation of physical fields of friction stir welding for aluminum alloy

基于热物理模拟构建的2024-T3铝合金Arrhenius本构关系,使用Deform-3D软件建立了搅拌摩擦焊三维热-力耦合模型,模拟焊接过程温度、应力、应变等物理场在塑性变形区的分布状态.结果表明,各物理场受焊速和转速的影响均呈不对称分布,其中材料在前进侧表现为压应力状态,在后退侧出现受拉应力状态;此外,在前进侧材料分别向焊缝表面和根部流动,当材料由后退侧向前进侧的流动速度小于在厚度方向上的流动速度时,在焊缝内产生缺陷,并通过试验验证了这一现象.

Based on thermal simulation an Arrhenius type constitutive relationship of 2024-T3 aluminum alloy,the 3D thermodynamic friction stir welding( FSW) was modeled by Deform-3D software. The physical fields including temperature,stress,strain were investigated during friction stir welding. The results reveal that all the physical fields are unsymmetrical in cross-section due to rotation speed and travel speed. The material appears compressive stress in advancing side( AS) and tensile stress in retreating side( RS),respectively. Furthermore,material respectively flows to the surface and bottom of weld in advancing side,which results in defect occurrence when the material flowing speed from RS to AS is lower than that of in thickness. The phenomenon is in good agreement with the corresponding experimental results.