only version of the connected problems not previously 13

 Ansys 13 and higher

I think you will have to use ANSYS's APDL (Ansys Parametric Design Language) to setup your model. Thus, some scripting will be necessary. Furthermore, consider reading about ANSYS's Birth&Death mechanism to dynamically create/activate elements as your process proceeds. Maybe you can search for publications simulating welding with ANSYS and find more inspiration there (simulation of welding and metal based Additive Manufacturing is somehow similar).

Yes. You can use APDL to set up your executabel command or macro. You need to read about Material Type command in ANSYS for having a domin with two different materials with different properties.

Thank u all for your responses. I will try it out .