Rigid-flexible Coupling Dynamics Analysis Of Multi-crane Lifting System Based On ADAMS

With the development of economic construction in our country, the large-span and extra-heavy structures has been used more frequently in the hoisting industry, as the multi-crane lifting system can make full use of the existing crane resources and complete the larger tonnage and span lifting, people must give to more and more attention to the multi-crane lifting system. However, in the process of hoisting, the multi-crane system is generally in a statically indeterminate state, at the same time, the boom and structures often have certain flexibility, and the cable may be influenced by gravity and inertia force, it is difficult to obtain the cable force state of the multi-crane lifting system so as to the control of the multi-crane lifting system been more difficult.Because of the complicated stress stain of multi-crane lifting system, and when the number of multi-crane lifting system is four or more, the system is in a statically indeterminate state. At present, in the actual hoisting process, the cable force distribution often calculated according to the experience of the engineer, thus may have some hidden dangers in the multi-crane system working process. Therefore, it is significant to obtain the loading history accurately for the safety hoisting of multi-crane lifting system. In this paper, take the multi-crane lifting system as the research object, the main work are as follow:(1) On the basis of thorough research to the hoisting process for multi-crane lifting system, the typical hoisting process of multi-crane lifting system was been analyzed detailedly. The influence factor of cable force loading history such as crane operation delay, start-brake acceleration and crane hoisting speed have been speculated.(2) The rigid-flexible coupling dynamics model of the multi-crane was built, according to the characteristics of the multi-crane lifting system and modeling method of the rigid-flexible coupling, the rigid models such as the chassis, turntable and mast have been simplified, the flexible models such as the boom, super mast have been built, so as to the cable model based on discrete nesting force. Then corresponding constraint pairs and the driving motion are applied to the components with relative relations. Finally, the rigid-flexible coupling dynamics model of multi-crane lifting system was built.(3)The factors may affect the cable force state was analyzed by simulation with the multi-body dynamics simulation software ADAMS. By changing the different operation delay state, start-brake acceleration and hoisting motion speed, just changing single variable, the influence effect of every factor for cable force of multi-crane lifting system was verified? Furthermore, the corresponding improvement measures are proposed according to the analysis results.(4) Based on the analysis of the influence factors on the load history of multi-crane lifting system, the cable force load process of module of multi-crane lifting system was developed. The influence factors such as operation time delay, start-brake acceleration and hoisting motion speed can be parametric input in this module to obtain the cable force history of multi-crane lifting system, so as to provide an important reference value for the safety listing of multi-crane lifting system.