Numerical simulation of three-dimension stress field in double-sided double arc multipass welding process

A new high-efficiency method for welding thick plates of low-alloy high-tensile steel which does not require back chipping – double-sided arc welding (DSAW) – is provided in this paper. Backing run adopts double-sided pulse gas tungsten arc welding, and other passes adopt double-sided gas metal arc welding. Three-dimensional numerical models of DSAW with 50 mm plates are developed to predict the stress distribution by using finite-element analysis, computer parallel processing technology and multiple jobs design, and are compared with single arc welding (SAW). The analysis of the interpass stresses indicates that the stresses of the back and cover pass are to be regarded as the key point in multipass welding. To verify the calculated results, the residual stresses and transient temperature of back run weld measured individually agree approximately with the calculated results, which illustrates that the backing run and residual stresses of DSAW are lower than those of SAW.