Chapter Construction of a Practical Finite Element Model from Point Cloud Data for an Existing Steel Truss Bridge

Abstract

The objective of this paper is to develop a semi-automatic method for constructing a practical finite element model from point cloud data of an entire span of a through-type steel truss bridge. In the first step, we introduced practical finite element models for truss bridges based on structural experiments and numerical analyses of a sway bracing located at the end support. We also proposed a basic method for semi-automatically constructing a finite element model of a sway bracing using point cloud data. This method was then extended for an entire of steel truss bridge. The point cloud data is converted to individual data structures which, in turn, are connected to construct a whole structure. The main members, such as upper chords, lower chords, and diagonals, are converted to fiber-based models by automatically creating central axis lines and cross-sections from the point cloud. The slab is converted to shell models by obtaining surfaces and thickness from the point cloud. The effectiveness of the proposed method was confirmed by comparing the analysis results from the finite element model manually created from the design drawing (drawing-model) with those obtained from the model generated by this method (point-cloud-model). The proposed method is more efficient than reading drawings and creating the models manually, and it was confirmed that the point-cloud-model shows response values close to those of the drawing-model within the design load. However, the reproducibility of the response values with more than the design load remains an issue, which can be solved by tuning plate thickness