What type of contact set to be used between welded parts ?
how to determine the mesh type and global element size ?
What type of contact set to be used between welded parts ?
how to determine the mesh type and global element size ?
You need to be careful with how much relevance you place on FEA results where a weld takes place; as Jared pointed out, welds are complex joints. Not only will the material properties differ (due to the mixing of the base metal and the filler, phase changes in the base metal due to the high temperature), but you'll also have residual stresses around the weld. Most importantly, if your weld doesn't have full penetration, then you need to capture fracture mechanics.
bonded contact = welded or glued
but welds are a really complicated topic, there may be combination between no penetration and bonded depending on how you are "welding" things. but start with bonded.
mesh type is based on the type of part, blocky part = solids, thin part = shells, long slender = beam
element size, start coarse and refine as needed, see topics on convergence