The Diagnosis On The Fault Of The Supporting Cylinder In The Portal Crane And The Fatigue FEA Research On The Gantry Structure Based On The MSC. Fatigue

Currently, in our country's big and medium-sized metallurgy companies, in order to Expediently rising moving and unloading the works, we adopt a lot of cranes Among them includes a lot of port cranes,, However, in recent years, along with the highly developed economy of our country, the production of steel rises increasingly, the load works of cranes have enlarged greatly, so there appears all kinds of metal problems Among these problems the most in number and also the most serious is the trouble in crane metal structures which mostly are troubles of fatigue crack.This paper takes two port cranes in Maanshan Iron & steel Co. Ltd as the research object. And takes a research on a segment of surface crack which lies in the supporting cylinder. Processes the systematic valuation of security and homogonously gives repair suggestion.First, this paper discusses the importance of preceding the research on the crane metal structures and especially the research on the surface cracks, this paper also introduce the theory: the fracture mechanics and software such asMRC, PATRAN and fatigue research software: MSC. Fatigue, then it put the main content of the problem and elaborate its significance in theory and practice.Second, this paper gives the finite modeling and calculation to the port crane's supporting cylinder. In the processes of making modeling, we take more attention to the making of the 3-D surface cracks, by the intension analysis, we make such conclusion that the surface crack is according with the static intension but there is big stress intensity in the surface crack. Also because the supporting cylinder sustain the varying fatigue loads, it shows that the crane's supporting cylinder may face the fatigue wreck. So in order to diagnose this surface crack clearly, this paper use the theory of mechanics to research and analysis the crack. The result shows that those two cracks will extend under the formal loadings, we put forward some schemes of che modification. Then we use the FEA software to analyze the structure again, and the theory calculations and the practical results shows that our scheme on the modification is successful.On the bases of introducing the technology on fatigue FEA, this paper also make use of the software MSC. Fatigue to proceed the fatigue analysis on this metal structure under certain loads, by the analysis, we can get the cloudy pictures of the fatigue life distribution, and can clearly see every part's fatigue life.At the end of this paper, some conclusions on this subject's practical and academic signf icance are presented, this paper also submit the research di reetionsin the future.