Research On Optimization For Auxiliary Bracing Of The Boom System

To meet the demand of lifting height in producing, lifting and manufacturing industry, the length of boom is growing year after year. So are the problems. The first one of them is the erecting problem of large-scale boom. As a result, the auxiliary bracing is set up to solve this problem. Although the auxiliary bracing has been set on the crawler crane of each type, the design work about it is still based on trial method which would cost lots of time and labor. To get rid of this time and labor consuming method, the rules about how to design the auxiliary bracing device from different aspects are explored and a practical method is proposed to design it. The specific work is as bellows:(1) The pattern, feature and installation type of the auxiliary bracing and the effect on the boom are introduced briefly. As well as the research situation of auxiliary bracing.(2) Because of the redundancies to model the boom each time, it is required to simplify the model with some accuracy. The pros and cons of simplification methods for two types are discussed, and a new way is designed to simplify the boom model due to the particular requirements for the non-neglect non-uniform section.(3) Based on the former work about the auxiliary bracing, the conclusion how it influenced the boom system entirely in two typical working conditions has drawn. Additionally, with the single factorial analytical method the influence of each design parameter of auxiliary bracing on the boom system is analyzed. Eventually, these results are summarized and the principle is generalized among them.(4) The features of the large-scale boom system are analyzed. Firstly, due to the large length and small stiffness of the boom system which would cause large displacement but small stain, the geometric non-linearity should be considered. Secondly, for the large-scale boom system the second deflection effect could not be crossed out in engineering practice or research. Finally, the reverse-deflection which is derived from the auxiliary bracing in lifting condition should be considered as well.(5) A new first-order optimal process is developed, taking advantage of the optimization methods of ANSYS and avoiding their disadvantage to make best use of them. According to the availability of different optimization methods, the PSO optimization method is proposed for it suits designing the auxiliary bracing. Taking advantage of MATLAB and program, the optimization goal could be achieved. (6) The non-uniform section boom of660t crawler crane is taken as the practical example to figure out which one of the two methods mentioned above from such aspect as the optimization result, the convergence of each method and so on.