Static Stiffness of the Crane Bridges Under Moving Load Distribution

The paper deals with issues related to the calculation and design of prestressed crane structures of span type. The problem consists of the further application and use of a refined mathematical model of a preformed crane bridge, which allows analytically investigating its deformed behavior according to actual operating conditions. This paper analyzes the mathematical models of the main girders of overhead cranes adapted for use. The most dangerous positions for them with a movable transverse load are considered. The authors provide a refined mathematical model of an overhead crane with prestressed beams based on the general theory of stability of elastic systems. In the design scheme, the resulting vertical movable load was distributed over several transverse movable loads, corresponding to the actual conditions of its loading. In this work, equations for the deflection curve of a span were obtained, which made it possible to additionally investigate its static stiffness, depending on the nature and action of a temporary moving load. The results obtained in this work can be used to modernize cranes to increase their lifting capacity, extend their service life without dismantling, and improve existing structures and engineering calculation methods under actual operating conditions.