Considerations of various moving load models in structural dynamics of large gantry cranes

Abstract

The paper deals with the moving load problems within the structural dynamic analysis of a large gantry crane as high-performance machine. The emphasis is placed on combined method approach, i.e. finite element method and analytical postulations, to obtain the mathematical model of crane. Moving trolley is considered throughout several models: moving force, moving mass, moving oscillator and moving oscillator with swinging object. Each model has characteristics which determine the responses of the crane structure, along with its dynamic properties. The title problem is solved by calculating the forced vibration responses of the two-dimensional framework with time-dependent property matrices and subjected to an equivalent moving load. Improving the moving load models increases complexity as well for postulating as for obtaining the solutions from overall crane model. Comparative presentation of models is shown here with conclusion that leads to an appropriate way of model selection prior to crane problem postulation.

Keywords

• gantry crane
• moving load
• structural dynamics
• vibration