DESIGN AND OPTIMIZATION OF CRANE JIBS FOR FORKLIFT TRUCKS

Abstract

The purpose of this paper is to present a new calculation methodology via F.E.M. applied to crane jibs. This analysis was carried out in terms of strength and stiffness, and for any kind of crane jib: telescopic crane, lattice crane, closed beam crane, etc. Different loads and boundary conditions the structure might be subjected to were simulated. Loads were obtained from normal and extreme crane operation, likewise taking into account current regulations and previous experience. It was also necessary to define methodology to simulate non-structural elements, contacts, materials, etc. Regarding regulations, regulation UNE-58536 had to be adapted since the specific regulation affecting said crane jibs (UNE 1726), was not restrictive enough. Moreover, some translational and rotational speeds had to be estimated for regulation application.In addition, the welding of some parts was simulated and analysed. Comparative analysis was performed on the experimental and numerical resutls for some load cases. Once this correlation has been obtained the methodology of calculation and the numerical results are validated. Key words: jib, F.E.M., strength, crane, forklift truck, extensometry, telescopic, stiffness, , normative.