Finite Element Modeling of Thin-Walled Steel Structural Members from 3D Point Clouds

Abstract

Most steel structures are configured by assembling thin-walled structural members, and structural analyses of those structures are conducted using the finite element (FE) models adopting the shell elements. This study aims to construct a FE model of the thin-walled steel structural members from 3D point cloud data for use in the performance evaluations of existing structures. The experimental verification was conducted for a basic study; here, three specimens of steel members configured by assembling flat rectangular steel plates were prepared, and the point clouds were acquired by a 3D scanner. The first procedure of configuring 3D shell element geometry was the segmentation of each plate by adopting the k-means method. The neutral plane of each plate was then estimated by the principal component analysis. Furthermore, the identification of each plate size and the modeling of local geometry were performed by the edge extraction of point clouds. The FE model was constructed from the obtained neutral plane, and the validity of the models was verified by comparing the FE models created with the design parameters with the output from the static elastic analysis. It was shown that the FE model constructed from the PCD provides reasonable results for Mises stress distribution, maximum displacement and stress, and modal properties. In addition, the point cloud data of an actual steel plate girder bridge was acquired and took processing for verifications of applicability of the FE modeling procedure.