Automatic Laser-based Geometry Capture for Finite Element Analysis of Weld Beads

Fusion welding for high-value manufacturing requires strict process controls on component distortion and ascertaining levels of residual stress imparted to the completed component. The process is dependent on controlling a myriad of parameters, focusing predominantly on ensuring adequate fusion of parent material and consumables. High thermal gradients that are imparted during the process can result in significant distortion if left unchecked, and high levels of residual stress if the component is completely restrained. Finite element analysis is commonly applied in fusion welding processes to predict distortion. These models, however, almost exclusively use an idealized or simplified geometry defined before the start of the process, which can be unrepresentative of the final component. A protocol is described for capturing the true shape of a single weld bead deposition within a unique coordinate system using a laser scanning system and converting this captured geometry into a form that can immediately be incorporated into finite element analyses. This allows the finite element model to be rapidly populated with a geometry representative of the true deposition with limited user input.