Research On Fatigue Life Of The300t Rotary Floating Crane Structure Based On The MSC.Fatigue

The fatigue property of metal structure has been focused by people, metal structure of the fatigue performance study also widely spread in various fields. We begin to study fatigue late,but in recent years we get some significant results in fatigue study. As in crane field, Beijing lifting transportation machinery research institute and dalian crane factory make the fatigue test research about the crane under common condition.At present, computer simulation technology has been used in product design,and the finite element simulation technology has become an indispensable tool of analysis. Compared with the traditional test methods,the finite element simulation can provide the surface fatigue life analysis of parts,it can Judge weak position in the design phase of the fatigue life,so we can avoid unreasonable life distribution through the change of design.Through the search of references about fatigue in and abroad, we can understand fatigue development present situation, and through the study of the theory of related research, we can make prepare for the crane metal structure fatigue analysis theory In the related theory chapter, this paper introduces the fatigue and fatigue life theory, fatigue load spectrum and cumulative damage theory, and summarize the influence factors of the fatigue life of the metal structure.This paper take research on lift crane, we build the finite element model about the crane metal structure with MSC. Patran finite element software, and import it to MSC. Nastran,then get the static analysis result. At the same time, this paper also analyze the lift condition with the Crane ship,determined the more appropriate working condition,it makes prepare for the after fatigue analysis.When the metal structure meet the requirements of the crane design,in order to ensure the safe use of heavy conditon,we make modal analysis for the crane. The natural frequency of vibration of crane is a very important parameter. When the crane work,meet the strong wind and normal voyage in woking,we must avoid the crane from damage and vibration. At the same time, if the natural frequency of vibration of crane’s design is proper, it can make the crane operator comfort in the operation of the hoisting,and it avoid the error in fatigue operation which will cause unnecessary loss. According to the principle of crane dynamic, we use finite element analysis software MSC. Nastran to analysis the modal about the crane metal structure and extracting the first10order natural frequency and vibration mode.This paper uses fatigue analysis software MSC. Fatigue, analyse the fatigue of crane and get fatigue life of the crane,it provides the reference for the design of the crane.