Low-weight design of a monosymmetric box girder of a double girder bridge crane with two trolleys

Abstract

The paper presents the analysis and the optimization (weight reduction) of the two-trolley double-girder bridge crane box-girder by the Lightning Attachment Procedure Optimizer (LAPO) algorithm. The single-objective function workflow uses the geometric properties of the box-like cross-section plates and additional design elements as variables. This multicriteria optimization uses the maximum stresses in cross-section characteristic points, plate local stability, the stability of longitudinal stiffeners, global girder stability, structure's oscillation dumping time and maximum deflections as the constraint functions. The existing bridge design saw a significant weight reduction of 17.89% for material S355 and 16.90% for material S275. Finally, the features of the chosen algorithm and optimum solution change flow for ten simulations are presented for the best solution achieved for both materials.