OPTIMIZATION OF THE WELDED I-GIRDER OF THE DOUBLE-GIRDER BRIDGE CRANE

Abstract

The paper presents the optimization of the main girder of the double-girder bridge crane. The main girder is made as welded I-section. Standard rectangular rail for electric trolley running is welded over the top flange. The strength in characteristic points of the main girder section, girder deflection and its dynamic stiffness were analysed. Also, the influence of local bending stresses due to the trolley wheel - rail contact pressure as well as the girder lateral stability due to the ratio between the length and cross-section dimensions of the girder were considered. Thus, the analysis has taken into account the most significant influences for this type of structure. The optimization procedure was conducted by different numerical methods. The results are compared to manufactured cranes with standard rolled I sections as main girders.