Research On Using Life Of The Crane's Girder

Safety life of crane was determined by its fatigue intensity of metal structure. The existence of original flaw leading to early destroying of structure could not be predicted by traditional fatigue designing method of steel structure of crane. So it was inevitable that the cranes that were designed according to this method had hidden dangers. Many great steel-making plants were worrying about the serving cranes that were bought in the 70's.Considering the influence of material original flaw, the thesis gave the 4# 125t crane of NO. 3 steel-making plant of Maansan steel CO. for example to analyze the designing and remaining life of the crane's girder by using damnification limits design method. The method was based on the theory of rupture dynamics and the principle of disrepair-security. The thesis offered the theoretic basis for safety running of the crane.This girder was analyzed by using ANSYS. The FEM model was accurate andeffective by using submodel and error estimation technique that ensured the reliability of calculation and analysis.The thesis got the measure of critical flaw and designing life of the girder. In addition, the thesis calculated the remaining life of the girder while the flaw reaching 150mm. The project that the crane must be repaired immediately and stopped using in limiting time was offered to the plant.The thesis complied parametric program by using APDL. The software to estimate the performances of the crane's girder being complied by VB language was offered which would improve the efficiency of building FEM and analyzing remaining life of crane.At end of this paper, some questions were presented. The author wished to cause the relevant division's attention, and be solved in the future.