A COMPARATIVE STUDY OF ANALYTICAL AND NUMERICAL ANALYSES OF THE STRUCTURE OF THE DOUBLE-BEAM BRIDGE CRANE WITH THE RAIL IN THE MIDDLE OF THE MAIN GIRDER

Abstract

This research deals with the analysis and comparison of the results obtained analytically and by using the finite element method on the box girder of a double-beam bridge crane with the rail in the middle of the girder, where an existing bridge crane, which is in use, was observed. Stress states in the girder were observed in this analysis, and the emphasis was placed on the local stress states which occur in the middle of the girder due to the wheel-rail pressure. The expressions used in the domestic literature and applied in the design of these types of structures were used for obtaining analytical values of the results. The software package SAP2000 and the software module Autodesk Nastran In-CAD of the software package Autodesk Inventor were used for the FME analysis, where the girder structure was modelled by shell finite elements in both cases. In the application of the software package SAP2000, the rail was modelled by beam finite elements, and the loads were applied on the nodes of the finite element mesh which connect beam and plate finite elements, while in the application of the software module Autodesk Nastran In-CAD the rail was modelled by 3D finite elements, and the loads were applied on the external rail surfaces which are in contact with the wheel. The aim of this research is to present the comparison between analytical and numerical results in order to justify the application of the proposed models of FEM analysis, their advantages and disadvantages, as well as the credibility of the obtained results in relation to the existing analytical model of calculation. In this way, it can be shown whether the FEM results are within those obtained analytically, so that in the design of these types of structures the proposed modelling methods could be reliably used.