Three-dimensional finite element analysis of thermal stress in single-pass multi-layer weld-based rapid prototyping

The complex thermal stress and residual stress distributions in the weld-based rapid prototyping process could cause large deformation and even cracking. In this paper, the thermal stress evolution, and the residual stress distribution in a single-pass multi-layer weld-based rapid prototyping are examined, and the effect of depositing directions on the residual stress and residual strain is studied by numerical simulation, after experimental verifications of the finite element model. The results show that the predicted residual stress variation trends are generally in agreement with the experimental results. The deposition of the last layer dominated the residual stress of whole component. This is due to the stress release effect of the rear layers on the fore layers. Besides, depositing directions have significant influence on the residual stress and equivalent plastic strain distributions of components, where the deposition in the reverse direction acquires the better result.