Thermo-mechanical coupling and part-level analysis for additive manufacturing processes

The additive layer manufacturing (ALM) process is an advanced and promising technique for future
manufacturing of complex metal parts and components[1]. The significant and challenging factors that
determine the final material characteristics are the thermal distortion and thermal stresses in the specimen,
which develop during cooling and shrinkage of the solid phase part layer when the laser has passed. In
principle, the mechanical and thermal properties also vary with material temperature. The laser as a
heat source is modelled in the heat equation for transient thermal analysis. The J2 elasto-plastic material
model is used under the infinite small strain assumption. While the thermomechanical coupling is based
upon quasi static analysis approach. Here the thermal loads overlaying with thermal conduction are
applied at the specimen, which undergoes elasto-plastic deformation. For descretization of the problem,
the Finite Element Analysis (FEA) platform deal.ii [2] is utilized. This primarily not only predicts the
part-scale temperature profile and distortion displacements but also trends of thermal stress state as a
result of the laser heat source applied to a solid Ti-6Al-4V specimen. Consecutively, the basic multiphysics thermomechanical system is established. This can soon be further developed for adaptive FEA
and elements activation in the ALM process with added material layers.