Computational Simulation of Shaped Metal Deposition

Abstract

Shaped Metal Deposition (SMD) is a novel technology to build near-net shaped pieces by weld deposition. The pieces we are interested in are aerospace components made of Titanium alloys. Given such expensive material, the reduction of scraps thanks to near-net shaping is crucial. Although already operational, the process still requires a great deal of manual intervention and control. Our research focus then on developing computational models of the physical phenomena involved in SMD as a first step to its automatic control.
This work deals with the modelling of the thermal field developed during SMD, which is basically a multi-pass TIG-welding process. The problem to be solved is the transient heat conduction induced by a highly concentrated heat source representing the welding arc. Being a multi-pass welding problem, we have to deal with cyclic temperature variations, including successive melting and solidification.
The problem is solved using linear triangular finite elements, with the phase change terms evaluated using the discontinuous integration technique developed by the authors in a previous work.