The Theoretical Analysis And Experimental Study On The Strength And Stability Of Crane' Drums

With globalization the performance of ocean ships served for international business is becoming larger. Today the maximal volume of a container vessel has been even 8000TEU and the loading capacity of a bulk cargo ship could be up to 400,000 ton. Consequently, the speed of port cranes is higher and its size is larger. This means that the requirements of the work performance on a cranes' key part is also higher. Under this background the engineering practice shows that the traditional design method of a drum wall could be conservative. Such designing method often leads to a thicker drum wall which causes not only difficulties for welding drums' bending and machining, but also let increase the machines' own weight, i.e. reduce the effective performance of the cranes. Thus it is necessary to find out an reasonable approach for design of drum's wall based on scientific theory and experiment.To meet this challenge, a research project was supported by Ministry of Communication and bv Shanghai Zhenhua Port Machinery Co..Ltd. Focusing on analysis ofTDTCD(Traditional Design Theories of Crane Drums) the paper has studied the impacts of features under the binding force of wire ropes, the end-plate and rope slot. This study is based not only on the thin shell theory and viscoelastic mechanics to calculate the strength and stability of drum, but also on an experiment with technology in "state of act". Therefore the results could be used to improve the traditional calculation, and it is a promotion for the standardization of drum design.Viscoelastic mechanics theory was used as the basis for the displacement and relaxation experiment of wire rope structure. The study the time co-reliance of wire ropes was finished and the calculation model for the wire rope relaxation amount was proposed. In the light of the time co-reliance of the wire ropes, the calculation formula of the rope tension efficient was deduced through the law of Conservation of Energy before and after the wire ropes ware rolled. Moreover, the feature problems of the load outside the drums under the binding function of the wire ropes were solved and the calculation method concerning the rope circle tension was derived.Based on the strength design theory and the practical stress features of the drums and on the phenomenon that the drums produce the circumference stress along the drums under the binding force of the wire ropes and the bending stress along the axis, the paper proposes the fourth strength theory as the basis for the drum strength design.On the basis of mode experiment of the drums, the paper analyzes the impacts of the drum end and the gradual wind of the wire ropes on the drum strength. And also on the basis of the analysis of the data of the drum mode experiment, the paper presents the research conclusion that unstability mostly occurs where drums are fully wound with wire ropes. Andbased on the consideration of the impacts of the drum end plate, surface rope slot and quality change of the wire ropes, the paper has deduced the theory calculation formula of the drum stability.Through developing the comprehensive experiment device with large-scale drum strength and stability, the stress-measuring experiments of various wall thickness of the normal drums of the cranes were performed. The law that the stress of the drums along the circumference and along the axis changes with the load increase of the wire ropes was studies for the first time. The data of the result indicated that the traditional method for drums' design is too safe to economy and it is absoluteness feasible to make the thickness of drums' thinner.Based on synthesis analyzed cranes drums' strength, stability calculate theory and abundant test, the dissertation also predigest the consider method of rope slot protruding stiffened and present corresponding calculate chart, the dissertation also discussed the drumd' strength and the judgment method of destroy modal of drums' stability and brought forward new drums' design and calculate method. At last, the paper...