3D reconstruction of welded joints from an unordered point cloud

Various fatigue assessment methods have been proposed to achieve more accurate fatigue life estimations over the past decades. However, most of these methods are proposed and developed based on idealized geometries of welded joints. Even slight variations in geometry details will significantly influence the precision of fatigue life estimations. Both global and local geometries should be taken into consideration to address this challenge. In this poster, we present a framework for 3D reconstruction of welded joints from an unordered point clouds. A high-resolution laser scanner was used to obtain the point cloud from a cruciform welded joint with capturing the geometry details. The point cloud was then sliced along the welding direction to obtain a series of sub-volume point clouds. In each sub-volume, the point cloud was ordered by using KD-Tree and then fitted with a quadratic B-Spline curve. 2D cross section models along the welding direction were reconstructed as an intermediate step. Based on the reconstructed 2D models, a 3D model was finally reconstructed using iso-surface extraction method. Finite element simulations were conducted on the reconstructed 3D model. The proposed framework supports stress analysis and fatigue assessment based on the as-built geometries of welded joints. Future work will focus on evaluations of different fatigue assessment methods with the aid of this framework.