Design And Optimization For Wind Power Lifting System Of Crawler Crane

As the increasing attention taking by our country on the field of wind power, some large-scale investment on the wind power project starts construction. It provides a large number of new energy for the whole society, and brings commercial opportunities for the wind power related industries at the same time. Playing a major role in the filed of wind power lifting, the crawler crane industry benefits from it. The characteristics of the wind power equipment in lifting progress are high lifting height and large lifting load. In the meanwhile, it must be strict with the work-radius to avoid the interference between the hanging objects and the main boom. In response to the feature, the manufactures have introduced special types of machine to be better adapting to the wind power lifting environment, and the most common method is providing additional wind power lifting system for the crawler cranes.The original boom combinations of the crawler crane are the design prototype of the wind power lifting system. According to the lifting requirements of the wind power lifting crawler crane, there must be some improved design of certain structures. The combination of the fixed jib is set as the basis for the design, The wind power lifting system is composed of the head of the main boom, the wind power specific jib, the luffing masts, and the stay bars. That makes a increasement in the working radius and the working height with the succession of the lifting property of the main boom. The head of the boom is the existing structure and need no more design, and we just have made the wind power specific jib and the luffing masts as the main object of our research, and done a design research on it. Details are as follows:1. In allusion to the design requirements of the wind power lifting system for the crawler crane and combined with its own structure of the QUY300 crawler crane, we draw up the design program for the whole of the wind power lifting system and do the model selection of its structure type, the steel wire rope winding system and the extract device.2. Based on the book《Design rules for cranes》, we have designed the structure of the wind power specific jib and the luffing masts. The wind power-specific jib and the luffing masts are the core structure of the whole system, and the design directly affect the overall performance. When in lifting operation, the angle between the lifting load and the luffing masts axis direction is small, which lead to the specific jib under axial pressure. At the same time, in the impact of the stay bars, the luffing masts is also under axial pressure. So, we make the stability of the bending resistance member as our main research factor of the overall design, and the bending strength as the main factors of the local design, as well as the main indicator of the feasibility of the design.3. Based on the finite element method, we have created the model of the wind power lifting system and made a static analysis about the whole system. In the meanwhile, do the buckling analysis on the specific jib and its luffing masts and the contact analysis on the local structure. By analyzing the results, we will be clear about the stain characteristics, the stress and the stress distribution of the constituent components of the wind power lifting system. And verify the feasibility of the design in aspect of stiffness and strength of the system.4. To improve the economy of the product, we set the system weight as our object function, and select the relevant structural parameters as the design variables to do the optimal design. The optimization problem belongs to the multi-variable linear programming. The key to solving this problem is to seek reasonable constrains. Too many constrains will lead to small feasible region and difficult to find the optimal point, while too few constrains will lead to large feasible region, so that the time of the search for the optimal points will be long. We select the overall stability, the single stability and bending strength of system's various components as the constrains and select the range of the design variables as the boundary constrains. Using the genetic algorithm supplied by the optimization toolbox functions in MATLAB to do the optimization calculation and get the Optimal results. Reinstitute the finite element model according to the optimal results and do the finite element analysis. By comparing the previous and the after results, we will describe the difference of the strength of the whole system, and explains that the utilization of the system's materials have been improved.