Weld Modeling of Thin Structures With VFT Software

Virtual fabrication technology (VFT) weld modeling software has been mainly used in thick-structure welding simulation. Recently both U. S. and European shipyards have shown strong interests in using the software to predict and control welding distortion of thin-plate ship panels. It is more complicated to simulate the welding of thin structures than thick structures because buckling distortion often occurs during the welding of thin structures. To evaluate the effectiveness of VFT for predicting distortion in thin structures, a bead-on-plate specimen, a butt joint of two large plates, and a long T stiffener were analyzed with VFT welding modeling software. By comparing the predicted distortions with those obtained by measurement, it was found that VFT can accurately predict welding-induced distortions of thin structures. Sensitivity studies show that pre-deformation induced by upstream fabrication processes and heat input are important factors influencing predicted distortions. Both distortion trends and magnitudes for thin structures are influenced by pre-deformation and heat input.