Research On The Fatigue Life Of The Main Beam Of The Crane

The requirement and the performance demand of the crane which as the engineering machinery product which replace human labor for material handling is increasing when our country's economic develop. the main beam is one of the most carrying structures, it has the direct influence on the performance capacity of the crane. The fatigue failure is a common destruction form. So it is very important to study the fatigue life of the crane's main beam, because not only it can take sufficient theoretical preparation for the increasing of the anti-fatigue property of the crane'main beam, but also can the save cost and time on the fatigue experiment.This paper combine the correlation theoretical research results, the finite element analysis soft of ANSYS and the fatigue life calculate soft of nSoft, through studying on the main beam of the crane. Complete following content:1.Studying the basic knowledge of finite element, summarize the knowledge of the apply of analysis of finite element, then study the impact of the restrict pattern on the result of finite element analysis, build the model of the main beam with the shell element and the solid element, compare the results, analysis the influence of meshing on the calculation result.2. Using the finite element analysis software ANSYS to establish the finite element model of the main beam, doing the static analysis of the finite model, getting the load time history of the structure by using the transient dynamic analysis methodology, getting the typical load cycle block by combining with the random lifting capacity which generated by the software Matlab, importing the result file of the finite element analysis into the software nSoft, using the FE-Fatigue module in the software nSoft to calculate the fatigue life with the material S-N curve and the Miner linear cumulative damage criterion, and getting the fatigue life, then research the influence of the gap between the separator of the main beam and the bottom flange plate on the fatigue life of the structure.3. Combining the case of a main beam of a container gantry crane being used generate fatigue cracks in a wide range, calculate and analysis correspond its structure according the method of this paper, analysis the influence of the distance between the centerline of the track of the trolley and the centerline of the main web on the fatigue life of the structure. Calculate the life of the structure by using the stress field intensity method. Compare the calculation results of different calculation methods with the actual life, verify the corresponding reference value index of this calculation method with the findings and conclusions of the calculation.This paper combine the statistical theory, finite element analysis and the calculation of the fatigue life successfully, this method can be used to estimate the fatigue life of the structure. The research give the theory preparation for estimate the structure of the main beam of the crane.