Research On Dynamic Simulation Of Floating Crane Based On Virtual Prototype

With the increasing commercial exchanges around the world,the trade,information,science and technology cooperation with the ocean as the carrier,linked by ocean development,international rescue and maritime transport,has become increasingly close.In the Marine development,rescue,transportation and other fields,the floating crane plays an important role.The floating crane has a wide range of applications.It is generally in the anchoring state when operating,thus the crane will be subjected to large waves and anchoring system forces.When the sea condition is relatively bad,the strong forced movement of the hull will aggravate vibration of the crane structure and the uncertainty of the moving track.Also the starting and braking of the crane will have a greater impact on the structure.All these conditions will lead to some dangerous situations.Therefore,it is necessary to analyze the dynamic characteristics of the crane in these cases.In this paper,aiming at the problems in the wharf test of the 200 t electric full-slewing four-link floating crane,the reasons were found through finite element analysis,and some structures were optimized.The crane boom is regarded as a flexible body,while the rest of the structure is regarded as a rigid body.The rigid and flexible coupling simulation model of the crane is established in ADAMS in combination with ANSYS and SolidWorks,and the luffing condition is simulated to verify the optimization effect.Considering the actual situation of the floating crane,the dynamic characteristic curves of the crane under various conditions are obtained by simulating the working environment of the sea area and the typical working process.The main achievements are as follows:Firstly,aiming at the problems of large boom vibration,luffing force and luffing motor power of floating crane,this paper analyzes the structure of crane box boom by using finite element software,and finds out the reason of the problem and then optimizes it.Secondly,in ADAMS,the simulation of luffing conditions is carried out before and after the crane optimization,and the displacement curve of the boom and the force of luffing screw before and after the crane optimization are compared to verify the optimization effect.Thirdly,considering the floating crane hull as a rigid body,the simulation of the whole crane was carried out after loading the external excitation load such as wave force in ADAMS,and the dynamic characteristic curves of the floating crane were obtained under different sea conditions,different hull wave direction encounter angles,different lifting rope lengths and different lifting weights.Also the dynamic characteristic curves of the floating crane system were obtained under certain circumstances,such as lifting weight off the ground,static acceleration in the air,emergency braking at a constant speed and falling of the weight.Based on the analysis of the dynamic characteristic curve of the floating crane,the paper points out some problems that should be paid attention to in the design and use of the floating crane,which can provide reference for the design and use of the same type of products.