Modeling and analysis technique of the hoisting system in the monorail crane

Abstract

The monorail crane system (MCS) is a part of the ITER neutral beam remote handling system (NBRHS) in the neutral beam (NB) cell to lift and transport the components during their remote maintenance. The MCS is composed of four hoisting systems at each corner of the crane trolley, which are driven by two independent hoisting motors and gear chains. As the MCS works in a radiation controlled area where human worker access is strictly forbidden and there are lots of important components inside the NB cell, the structural and dynamic behaviors of the MCS are crucial that need to be verified. This paper describes a modeling and analysis technique of the hoisting system in the monorail crane. The hoisting system includes two drums and one balancer with a payload attached on it. The kinematic and dynamic model of the hoisting system is developed both for a non-extendable rope and for an extendable rope. Differential–Algebraic Equations (DAE) are constructed and its solution technique is described. Free body pendulum response is analyzed to verify the dynamic model and the solution technique. The dynamic equations with the realistic one quarter model of the hoisting unit are developed considering the rope flexibility. Synthesized seismic accelerogram is applied as the excitation forces. The time response of the balancer and the payload is calculated. The result shows that the dynamic model captures the six degree of freedom motion of the balancer and payload well during the seismic events. This methodology is applicable to develop a full multi body dynamic analysis model of the monorail crane.