tailieunhanh - Analysis of dynamics of automobile cranes with the account of the rope elasticity

Up to now, there is still a little of attention paid on the dynamical analysis of automobile crane system and only simple dynamjcal models are used forth related studies. In this paper, a relatively comprehensive model describing the dynamics of automobile crane with only the body lifting mechanism taken into account, is presented. The numerical solution has been derived, illustrated by graphics and assessed. | Vietnam Journal of Mechanics, NCNST of Vietnam T. XX, 1998, No 1 (21 - 28) ANALYSIS OF DYNAMICS OF AUTOMOBILE CRANES WITH THE ACCOUNT OF·· THE ROPE ELASTICITY PHAN NGUYEN DI, BUI KHAC GAY Le Quy Don University, Hanoi ABSTRACT. Up to now, there is still a little of attention paid on the dynamical analysis of automobile crane system and only simple dynamjcal models are used forth~ related studies. In this paper, a relatively comprehensive model describing the dynamics of automobile crane with only the body lifting mechanism taken into account, is presented. The numerical solution has been derived, illustrated by graphics and assessed. 1. Introduction Automobile cranes are very popular loading-discharging tools. The study on dynamics of their working mechanism, however, is still limited and many related problems have not been solved adequately. In the literature, the models describing dynamics of automobile cranes are still simple [1-3]. The interaction between bodylifting and rodlifting mechanism are not taken into account and the role of the rope elasticity in the working mechanism of the system is not specified in these models. Thus, from the practical point of view, many problems have not been solved, such as how to keep the lifting body from shaking?, how the rod is shaking during the operation of the bodylifting mechanism?, how the movement pattern of the lifting body is when only the rodlifting mechanism works and what effects will be caused due to the elasticity of the rope?, . In this paper, a more comprehensive model for description of the dynamics of automobile crane in the case when only the bodylifting mechanism works and the numerical method for solving its basic equations are presented. The obtained results allow to assess the impact of elasticity of the rope on the system, especially the rod vibration even when the rodlifting mechanism does not work, the changes in movement pattern of the body and of the tension of the rope. 2. Model ' The .