Abstract: In order to predict the welding deformation of dissimilar steel structures quickly and accurately， a thermo-elastic-plastic finite element method was developed to simulate the residual stress and deformation of dissimilar steel welded joints. Based on this method， the inherent strain of Q345/SUS304 dissimilar steel plate butt joints and T-joints was studied. Furthermore， for complex Q345/SUS304 dissimilar steel welded structures， the inherent strain method and the traditional thermo-elastic-plastic finite element method were used to predict and compare the welding deformations. The results show that with the increase of the heat input parameter Q/h2， the tendon forces and transverse shrinkages increase approximately linearly， and the relationship among them and Q/h2 is obtained， while the angular deformations increase first and then decrease， which reach the peak value around Q/h2=12 J/mm3. The laws may provide references for prediction and control of welding deformations of large dissimilar steel structures in engineering. 

Key words: dissimilar steel welding, finite element method, inherent strain, welding deformation

摘要： 为快速准确地预测异种钢结构的焊接变形，提出了用于模拟异种钢焊接接头残余应力与变形的热弹塑性有限元法。基于所提方法，以Q345/SUS304异种钢平板对接接头和T型接头为研究对象，研究了其固有应变的变化规律。进一步针对复杂Q345/SUS304异种钢焊接结构，分别采用固有应变法和传统的热弹塑性有限元法进行焊接变形的预测和对比。研究结果表明，随着热输入参数Q/h2（h为板厚，Q为线能量）的增大，纵向收缩力、横向收缩量近似呈线性增大，而角变形先增大后减小，且在Q/h2=12 J/mm3左右处出现峰值。该规律可在工程上为大型异种钢结构的焊接变形预测和控制提供参考。

关键词: 异种钢焊接, 有限元法, 固有应变, 焊接变形