A 3D transient analytical solution to the temperature field during dissimilar welding processes

• We find an analytical solution to the thermal field around a moving heat source.
• The solution can model the asymmetric thermal field during dissimilar butt-welding.
• We use the established solution to simulate the dissimilar friction stir welding.
• The analytical results are compared with the numerical results obtained by ABAQUS.
• The analytical results and the numerical and experimental results are in good agreement.

Finding an analytical solution to the temperature field around a heat source moving along the interface of dissimilar materials butted together can extend the application of moving heat source solutions including various dissimilar joining processes. Thus, this paper devises a novel analytical solution to the three-dimensional transient temperature field for the above-mentioned problem, which can serve as a viable tool to predict the temperature distribution induced by a heat source, as a welding beam or tool, moving along the interface of a butt joint. Consequently, the devised solution can provide useful insights into material modeling and response in a variety of industrial applications. Meanwhile, to put the solution in a more general form and make it more convenient to use, we have expressed it in the form of Green's function. Finally, the numerical example is presented for one of the most remarkable applications, dissimilar friction stir welding, and analytical results are compared with those found via FEM commercial software and experiment to validate the developed solution.