Consideration of moving oscillator problem in dynamic responses of bridge cranes

Abstract

The dynamics of an overhead crane system with the suspended payload on the trolley moving at a specified constant speed is considered in this paper. The beam is discretizied by 10 elements, while the trolley is modeled as particle along with payload suspended with rope system modeled as spring. The overall mass, damping and stiffness matrix is calculated at each time interval, along with finite element formulation of equivalent force vector. Equations of motion of MDOF system are given for oscillator moving on beam structure. Dynamic responses in the vertical direction for all DOFS are obtained by solving the governing equations with direct integration method. For validation purposes, the technique is first applied to a simple beam subjected to a force moving along the beam with constant velocity. The influence of moving velocity and spring stiffness are investigated.

Keywords

• moving oscillator
• crane structure
• transverse vibrations
• dynamic response
• direct integration