Dynamic Behaviors of Gantry Cranes. 5th Report. Natural Frequency.

Abstract

For the design of material-handling equipment like gantry cranes, for which large size and high performance have been demanded, it is important to evaluate their dynamic behaviors. In this paper, the dynamic behaviors of gantry cranes with loads are analyzed by the method of modal analysis, and the main factors having effects on the natural frequency are investigated. On analysis, the coupling of deformation behaviors in the horizontal and vertical directions is considered. The importance has been clarified from a series of studies. Moreover, simple equations for calculating the fundamental natural frequency in structural parts of a crane with a load are proposed. The results from these equations are in good agreement with those from the experiment using an actual crane, and the equations are useful for the design of gantry cranes.