Structural dynamics of big gantry crane subjected to different trolley move laws

Abstract

The present work concerns the oscillations and therefore the displacements present on a portal crane in the case in which the trolley is moved with different laws and in particular with different maximum accelerations. The work also investigates the effects of an abrupt stop of the trolley movement and also how the load oscillations, following the stop of the trolley movement, generates vibrations in the crane structure which are correlated to the crane natural frequencies. The work was developed on a real geometry of portal cranes using the finite element method. A new procedure was developed and implemented to simulate variable forces on the crane i.e. the forces induced by the trolley movement. The results show that in determinate conditions, the displacement and therefore the relative oscillations are very significant and therefore cannot be neglected.