Study On Vibration And Twisting Dynamics Of Distributed Mass Load Of Double Pendulum Tower Crane

With the multiworking steps of lifting,horizontal transportation,rotation,tower crane achieve the vertical and horizontal transportation and lifting of goods.The utility model has the advantages of small occupation area,large working space,wide operation field of vision,etc.,and has become an indispensable special mechanical equipment in the modern industry,the construction industry and the military engineering.However,the vibration problem of under actuated mechanical system greatly affects the accuracy of transportation,production efficiency and safety.Previous tend to tower crane system is simplified as a particle load pendulum model,or the hook and load are both simplified into particle of the double pendulum model,and on this basis on the dynamic characteristics and vibration suppression to do a lot of valuable research work.But tower crane practical load with specific physical dimensions,whether simple pendulum model or double particle of the double pendulum model,has the very big disparity with the actual crane load movement.Such as the slender beam,truss of transportation and hoisting process,in addition to the common load swing problem,twisting problem which has a greater impact on the safety of surrounding environment,positioning accuracy needs more attention.It is more difficult to ensure the safety.Therefore,the cost of the simplified model of the previous tower crane is the low robustness to the actual process of oscillation suppression and it is difficult to meet the actual needs.So the establishment of the model of double pendulum tower crane with distributed mass,and in-depth study of the double pendulum vibration of the mechanical system of tower crane and the twisting dynamics characteristics and its control has a great practical value and scientific significance.In this paper,the load transportation model of tower crane is simplified as a double pendulum structure.Hook volume is much smaller than the load so it can be approximated as a particle.Load volume is more larger,so use distributed mass model to represent it.In the end,a model of double pendulum tower crane with distributed mass is established.The influence of system parameters on the natural frequency of the system,and the dynamic characteristics of load vibration and twisting are studied in depth.The scientific contribution of this paper is as follows:Establish the model of double pendulum tower crane with distributed mass.Analysis of dynamic characteristics of load vibration and twisting of double pendulum tower crane.Design a smooth controller tosuppress its swing and twisting.