An Enhanced Mathematical Model for Investigating the Dynamic Loading of a Slewing Crane

Abstract

A fatigue analysis of a structure is nowadays a common part of the design process. One of the fundamental pieces of information for ensuring the high quality of the analysis is details of the dynamic loading of the structure. This information can be provided by means of a simulation using an appropriate mathematical model. In this article, a new mathematical model of a slewing crane is presented on the basis of the experiences gained with a previously developed model. Only the slewing motion that produces the spatial oscillation of the payload is considered, as this motion has received less attention than the translation of the suspension point. The mathematical model takes into account the non-linear nature of the swinging motion for large angles and the non-linearity of the power transmission to ensure sufficient accuracy. The structure's elasticity and damping, the friction in the main bearing, and the air resistance were also taken into account. The angles of swinging of the payload and the dynamic forces acting on the steel structure of the crane during payload transport were obtained. Measurements on an actual model of a crane were carried out for the purpose of confirmation of the mathematical model. The comparison of the results was executed and a good greement between the predicted and the measured values was observed.