FAILURE ANALYSES OF TOWER CRANE USING FEM AND THEORETICAL STUDIES

Abstract

This paper describes the technique to explicitly increase the tower crane's stability during cyclones through modal analysis in FEM. For this, modal analyses of a boom, mast, and tower crane are carried out individually to minimize the tuning effect of natural frequencies. The study explains the methodology to increase the stiffness using bracings in the mast expressed in modal parameters. In FEM analysis, bracings are applied in fixed support along the vertical mast of the tower crane. For this purpose, a 1/10 scale model of “Potain MCi85 A/B” tower crane was modelled in Nx-Unigraphics. Theoretical analysis of the boom's natural frequencies and its counterweight is assumed as cantilever beam and mast in form column. The values of natural frequencies of tower cranes under different boundary conditions are obtained through Galerkin and Dunkerley’s mathematical expressions. Theoretical and FEM results established similar trends of increasing stability as revealed in terms of natural frequencies of the tower crane.