Study On Based On Similarity Theory In Finite Element Analysis Of Gantry Crane Main Beam And Optimization Design

With the development of science and technology and social development levels, gantry crane become more and more important in the actual engineering, such as assembly of large ship, laying of railway and metro rail, etc. In order to meet the needs of engineering construction, gantry crane is required to carry biggish and complex load in the actual, and also has strong environment adaptability. So the gantry crane has already developed toward directions of large-scale, specialization and intelligent. But the original design concepts and its testing method of gantry crane can’t meet the demand of practical production increasingly. For this reason, this paper adopt the new design concepts and design method for static, dynamic analysis and optimization design of gantry crane girder frame.In this paper, using the similarity theory and dimensional analysis to get the similar relation of research parameters of gantry crane girder frame between models and prototype, setting to choose 6 kinds of zoom ratio models and finite element analysis in two stations and getting the corresponding analysis results. Researching the influence between similar ratios and results of the analysis and the relationship between similar ratios, and discussing the selection of similar ratios. Focusing on several important key points in practical application and exploring the rules between stress analysis results and the selection of similar ratios. Similarity theory is proved by examples that has obvious advantages in processing large steel structure. It will be using resources reasonably, reducing workload of problem solving, saving time and get a fairly accurate analysis results at the same time.The traditional design method of gantry crane still adopts the way combined with traditional theory and the experiences summarized for many years. Usually tending to guarantee that gantry crane has large enough safety factor, so as to make the product quality and performance have shortcomings. Leading to some unreasonable component size, material cannot be fully utilized, structure bulky, and only making estimate about stress and stiffness for some key parts of the gantry crane. According to crane design standard GB/T 3811-3811, crane acceptance requires the determination of the corresponding load under different working conditions and locations. In order to make up for the inadequacy of the traditional design method, this paper takesWorkbench which is a collaborative simulation platform of the finite element software ANSYS as analysis tool, selects two stations of car which are located in the middle of the crane girder frame and the end of flexible leg, studies the gantry crane under dynamic working conditions. Analysis results show that the static performance and stiffness of the gantry crane meet the design specification requirements.The paper also takes Workbench which is a collaborative simulation platform of the finite element software ANSYS as analysis tool for modal analysis and prestressed modal analysis of the gantry crane girder frame, solves and analysis the dynamic characteristics of gantry crane to get the top six levels vibration frequency and the corresponding vibration mode of the crane girder frame. Based on a natural frequency to measure dynamic rigidity of the gantry crane girder frame, according to the results to find the weak links of dynamic performance of crane girder frame. The results show that the third and fourth order natural frequency of the gantry crane are close, the crane girder frame will come into being transformation seriously from the third order to fourth order, causing crane work fault easily that need to be controlled and improved.Based on the static and dynamic analysis that gantry crane girder have a greater safety margin, so the paper makes a optimization design. Taking lighter weight as the goal and the parameter values are satisfied with the crane design specification as constraint conditions. Considering the actual situation, the paper focuses on the main girder and flexible leg and defines nine design variables, takes Design Exploration which is one module of Workbench as the optimization method to optimize and get the final optimization results. At last the whole research reaches the goal of reducing weight, improves the shortage of the crane girder frame at overall, saves the cost of production and resources, shortens the production cycle, improves the overall performance of the crane.