Study On The Fuzzy Reliability Analysis Of The Loader System And The Fuzzy Reliability-Optimization Design Of Its Transmission Shaft

In this thesis, the fuzzy reliability analysis of the wheel loader system and the fuzzy reliability-optimization design of its transmission shaft were carried out by the fuzzy reliability and optimization theory.This thesis expounded the actualities and trend of the reliability study of mechanical system, and researched the theories and methods of the reliability distribution. The fault tree of the loader system is built after analyzing the structure of the loader system with the method of fault tree analysis(FTA). The whole loader system, its subsystems and its parts were analyzed qualitatively and quantitatively. The basic faults of the system and the cause productive of them can be ascertained with the help of the fault tree, which save much time and raise working efficiency. At the same time, the reliability of the whole loader system was distributed by the method of combining the failure rate with the important degree. And according to the idea of reliability redistribution, the reliability of theloader system was redistributed for insuring the reliability distribution of the loader's subsystem is correct.According to the load characteristics and design requirements of the transmission shaft, this paper established the reliability-optimization design model with fuzzy mathematic and optimization theory. Then the fuzzy reliability-optimization design model was transformed into conventional optimization model, and the optimal results were obtained by optimum procedure programmed.