利用ABAQUS有限元软件对铝-钢异种金属冷金属过渡（CMT）焊接过程中焊接接头应力分布进行了数值模拟，分析了应力分布的变化规律，并进行了试验验证。结果表明：不同焊接时间下，焊接接头在钢板和铝合金板侧的von Mises应力分布不对称，其中铝合金板侧承受的应力较钢板侧的小；在焊接过程中，近焊缝处的纵向应力由压应力转变为拉应力，横向应力在焊初始阶段为拉应力，随后变为压应力，再转变为拉应力；在铝合金板侧和钢板侧热影响区的纵向残余拉应力最大，分别为125，208 MPa，位于铝合金板侧和钢板侧的横向残余压应力峰值几乎相同，约为80 MPa；残余应力分布模拟结果与试验结果的拟合优度为0.75，证明了模拟结果的准确性。

The numerical simulation of stress distribution in aluminum-steel dissimilar metal welded joint during cold metal transition (CMT) welding was carried out by using ABAQUS finite element software. The variation law of stress distribution was analyzed and verified by experiments. The results show that at different welding times, the von Mises stresses unsymmetrically distributed at steel plate side and Al alloy plate side in the welded joint. And the stresses at Al alloy plate side were smaller than those at steel plate side. During the welding process, the longitudinal stress near the weld changed from the compressive stress into tensile stress, while the lateral stress at the welding initiating stage was tensile stress, then changed into compressive stress and then tensile stress. The longitudinal residual tensile stresses reached the largest values in the heat affect zone near the side of steel plate and Al alloy plate, which were 125 MPa and 208 MPa, respectively, while the peak values of lateral residual compressive stress were almost the same at both sides, which was about 80 MPa. The goodness-of-fit between the simulated and test results of residue stress distribution was 0.75, indicating the accuracy of the simulation results.