Three-dimensional thermal response of thick plate weldments: effect of layer-wise and piece-wise welding

Abstract

The thermal response of thick plate weldments under multi-layer and multi-block welding sequences is studied by the use of three-dimensional finite element models. The moving isotherm approach is applied to the modelling of inserted arc power and the temperature dependence of the material's thermal properties is considered as well. The addition of welded material that normally occurs during the welding is also simulated by the use of the element rebirth technique. Arc movement, welder speed, arc moving direction and the time lag between the sequences are also considered in this research. The results show that the number of layers in the welding of thick plates plays a significant role in the formation of the thermal profile, especially for those points that are located near the weld. For the far points this effect is very small and can be neglected. In the case of multi-block welding, the results showed that this kind of welding sequence not only changes the magnitudes of maximum temperatures but also significantly affects the distribution of isothermal surfaces in the whole domain. Moreover, the outcomes are practically feasible and the model can be recommended for analysis of thermal fields in thick plate weldments.