Research on the uprising dynamics of a double-carriage overhead crane system

Abstract

The dynamic characteristics, in the uprising phase, of an overhead crane carrying two carriages and a cylindrical payload are studied in this article. The crane system investigated mainly consists of a twin beam, two carriages, a rigid payload, and two wire ropes. A new analytical model, in which the beam, carriages, payload, and wire ropes are, respectively, considered as uniform Euler—Bernoulli beam, lumped masses, rigid body, and springs, is presented to describe the uprising dynamics of the specific crane system. The most distinguished characteristic of the model is the dynamic coupling deriving from the presence of a flexible beam, carriages, and the cylindrical payload. The kinetic and potential energies, during the pre-tensing and lifting phases, of the components in the system are presented in particular. Then, utilizing the Rayleigh—Ritz method, one can obtain the differential equations of the dynamic system substituting the energy into Lagrange's equation. The differential equations are numerically solved by the fourth-order Runge—Kutta method, and then some useful results representing the dynamic features of the system are obtained according to the calculation. The validity of the analytical model is demonstrated by an equivalent FE model created by ANSYS and ADAMS. Comparison of the results, obtained by two distinct approaches, indicates good agreements, which can be the validity evidence of the analytical model.