Research On The Statically Indeterminate Problem In Multi-crane Cooperative Lifting

With the using of large-span or high-ton structures, and limited by the lifting capacity of single crane, multi-crane cooperative lifting is being gradually used. While more advantages are shown, such as the high efficiency, high quality and economic, it is be used by more and more engineering companies all over the world.Because the crane is large and collapses easily, with the crane number of the multi-crane lifting system increasing, a new mechanical problem has been arised which is the solution of the statically indeterminate lifting problem. When the crane number of multi-crane system increases to or greater than four, the force calculation of the multi-crane lifting system will become the solving of statically indeterminate spatial force system. However, there is still not a scientific theory to solve this problem at present. The lifting scheme designers usually distribute approximately the lifting force in the practical engineering application, which is mainly according to design experience. The way to deal with the problem lacks scientific basis, and hidden danger of lifting exists.For the statically indeterminate problem, research of scholars mainly focuses on the study of plane statically indeterminate area at present, which can not be used in the resolution of space statically indeterminate problem. And a new method which can be applied to solve the lifting force of multi-crane lifting system and the statically indeterminate problem is proposed after studying and analyzing the lifting force of multi-crane system in this paper.Specific works of this paper are as follow.(1) Research on the characteristics of multi-crane lifting system. The first is the structure characteristics which include the characteristic of rigid-flexible coupling and the statically indeterminate problem in multi-crane lifting system. The second is lifting performance analysis of the multi-crane system. And the last is the analysis of influencing factors to the lifting force in multi-crane system, such as position of the gravity center, the structure movement and so on. All the analysis above will be the basis of solving the problem of lifting force in multi-crane system.(2) Research on the lifting force analysis method for the multi-crane lifting system. According to the analysis of the structure and lifting force characteristics in the multi-crane lifting system, this paper studies the calculation method of the lifting force and proposes a new method which can be applied to solve the lifting force of multi-crane lifting system by analysing the change of structure’s deformation state in the process of lifting with the rope groups taken as flexible bodies and the other parts of cranes and structure as rigid bodies. And the value for the actual lifting engineerings is also be illustrated by the analysis of real-life case and the comparison of simulation experiment via ANSYS and ADAMS.(3) Development of the lifting force analyzing system for the multi-crane lifting system. According to the research on the lifting force of multi-crane lifting system, a lifting force analysis system for the multi-crane lifting system is developed in this paper. The software module can be used as a submodule of "3D lifting simulation system". The module implements the solution, data output and lifting process display of the multi-crane lifting force, which provides a favorable analysis and simulation tools for the lifting scheme designer.