The Security Evaluation System Of Crane Structure And The Probability Research Based On Finite Element Method

The structures of a crane is an organic system whose functions is classified into many layers, if there is something wrong with one of the structures, which will affect the crane to work, even lead to the failure of the system, so the metallic structures are very important parts for a crane. Meanwhile, those failures that are caused by metallic structures account for a large proportion, therefore, it is necessary to take research on security evaluation of the crane's metallic structures. The probability of metallic structures is also a vital factor that affects the structures' safety, so some researches are taken on the probability of metallic structures in this paper, and Finite Element Method is applied in probability analysis successfully.This paper aims to confirm the technological status of a crane's metallic structures, taking the factors which affects cranes' performance into consideration, forecasting the crane's additional useful life, developing the software which is about the security evaluation of the crane's based on Visual C++. In addition, the probability analysis for a crane is conducted by using the famous software ANSYS.The general structure of the paper is below: there are seven chapters in all. In chapter one, we describe the researches on security evaluation of the cranes taken by experts in domestic or out, the status quo and the tendency in future. At the same time, the development and the application of mechanical probability, the subjects and the significance of the paper, those main works done in this paper are introduced.Chapter two mainly describes the theoretic bases on security evaluation of the cranes. In the second part of chapter two, the form and classification of crack is discussed in detail, reducing the formulae of the crack's spread velocity, controlling the forward spreading of the cracks based on the theory of rupture mechanics. In third part, we discuss those important technological performance targets for a crane's metallic structures, the status index, the weight for the parameters. A new method called stochastic mistiness is put forward to accurate the status index and the weights. We evaluate the crane's additional useful life , estimating the structures' status according to the deteriorate index.The contents in chapter three are technological base for developing the software of security evaluation of the cranes. The visual technology of orientated objects, the programming design language, the message of Windows and the program procedure are introduced in chapter three. Based on the theories inchapter two and chapter three, there is an application example of the software about security evaluation of the cranes in chapter four, we analyze the calculated results and confirm the status of the crane's metallic structures.The basic idea of Finite Element Method and finite element software ANSYS are introduced simply in chapter five. Three methods for probability analysis are recommended, they are Monte Carlo Simulation, Response Surface Method, Sensitivity-based Approach. An application example provided for the application of Finite Element Method in probability analysis. Three main procedures are described for probability analysis in ANSYS. They are the form of the model files, procedure for probability analysis, postprocess and distill of results, so theories and practices are combined tightly in this paper. In the last chapter, we sums up the research work and put forward some problems that are waiting to be done in the future.