Predicting welding deformation of panel structure using inherent strain method with consideration of structural restraint

• The influence of structural restraint intensity on the inherent deformation of Q345 steel T-joints was systematically investigated. • The effect of plate thickness on the inherent deformation of Q345 steel T-joints was experimentally and numerically analyzed in detail. • This article addresses the question of how structural constraints affect welding deformation and to what extent these effects are manifested, providing comprehensive insights. With the growing focus on welding deformation in the lightweight manufacturing of transportation vehicles, such as ships and automobiles, there has been an increasing demand in the industrial sector for developing inherent strain method using commercial finite element software platform to rapidly predict the welding deformation of large and complex structures. In the traditional inherent strain method, the inherent deformations of typical welded joints in a free state (i.e., longitudinal shrinkage, transverse shrinkage, and angular distortion) are typically converted into corresponding inherent strain components. These components are subsequently incorporated as initial strains into the corresponding welded joints for progressive finite element analysis to determine the total deformation of the whole welded structure. Theoretically, when each joint in the structure is weakly constrained by surrounding components, the accuracy of this method is acceptable. However, when the welded joint is subjected to strong structural or external constraints, the welding deformation results obtained through this method may significantly deviate from the actual situation. To investigate the influence of structural constraints on the prediction accuracy of welding deformation, two T-joints made of Q345 steel with varying plate thicknesses were selected as research subjects in this study. By integrating experimental measurements with numerical simulations, the influence of structural constraint intensity on the inherent deformation of T-joints was explored. Furthermore, using the inherent deformations derived from typical T-joints under different constraint intensities, the welding deformations of a typical panel structure were calculated, thereby clarifying the influence of structural constraints on the prediction accuracy of the total deformation of welded structures.