Finite Element Model And Dynamic Performance Analysis Of Overhead Crane Bridge Structure

With the growing scale of production, working performance of the crane made newer and higher requirements:the increased lifting weight, frequent work, flexible and reliable operation, and reduced weight and so on. Due to certain constraints, the traditional design of cranes has too many assumptions and simplifications in the calculation. The bridge crane designed in previous way did not work in the best conditions, tending to have too much safety factor, resulting in some material waste and manufacturing costs increased. In the premise of ensuring the safety, how to design and manufacture the crane of high performance and low cost is an important topic worthy of further study. Researching and designing the crane by the use of modern design method (dynamic design method etc.) may well be an effective technical way. Establishing the finite element model of the mechanical structure which is designed by the traditional way, then researching and analyzing the model’s dynamic characteristics, and then reviewing, modifying or redesigning the structure to achieve optimization purposes. Therefore, the dynamic analysis of cranes, targeted to applied to product design stage, to improve its structure to make it more reasonable, lower equipment costs and more cost-effective, has important practical significance.Crane operation is characterized by agencies frequent startup, acceleration, deceleration and brake, have make the bridge structure constant shock and vibration. The dynamic performance of the bridge structure has a great impact on the overall performance; affect the structure’s dynamic strength, dynamic stiffness, motion accuracy of transmission mechanism and driver’s comfort and so on. The topics to partial double-rail box girder bridge crane for the study, using the crane dynamics and finite element method as the theoretical basis and analytical tools. Use of finite element analysis software ANSYS establish finite element model of the bridge. The paper mainly on two working conditions which are the fully loaded car located in the middle and end of the main girder. Using ANSYS software do a static analysis on the bridge structure of bridge crane, got the size and distribution of load stress. Through the modal analysis, the first four natural frequencies and vibration modes are calculated. The strength and stiffness of the bridge structure are checked. The bridge’s strength and stiffness has a large surplus. Through the transient dynamic analysis with the full method, the displacement response curve in the mid-span and maximum dynamic displacement are calculated when the fully loaded car in the mid-span location and bridge structure comes under the lifting impact load. Through the optimization module of ANSYS software, aiming at minimizing the total weight of bridge structure, by changing the section size of the main girder, satisfying the bridge’s strength, stiffness and process requirements, the paper made optimization to the box-main-girder. The weight of a single main beam reduced24.47%, with considerable economic potential.This study provides a new way for optimal design of bridge structure. The conclusion derived from the study has some engineering application value on the design of the crane’s bridge structure.