Based On The Fourth Moment Of The Mechanical Reliability

Reliability as one of mechanical products quality characteristics,which is paid attention to users. High reliability of the mechanical product not only can make the enterprise gets good economic benefit, but also can in market competition for good reputation. At present, the domestic and foreign experts and scholars do numerous scientific researches on the reliability. In view of the actual engineering data belongs to a small sample and the sample data can also obey various distribution function, this paper mainly on the following three aspects of the research work.First, the sample data with the first four moments of Taylor, Edge worth series is proposed, which combines calculated based on sample first four moments of mechanical parts reliability method, establishes the mechanical parts of the single objective and multi-objective mathematical model in MATLAB, and then write M file in the MATLAB environment, use MATLAB optimization toolbox for example calculation, and finally to verify with Monte Carlo method.Secondly, in view of actual project data in small samples of random variables, which can be subject to a variety of distribution forms, in the project usually see random variables as normal distribution to be calculated .So put forward making use of software ANSYS to analyze sensitivity of engineering machine, which suffer random variables subject to arbitrary distribution function and study each random variable the degree of influence on the mechanical reliability. Put spherical pressure vessels and beam as example to determine the degree of influence of the various random variables on pressure vessel and beam. Then based on four moments reliability sensitivity analysis method, as spherical pressure vessel for example to analyze, the results are same to actual situation.Finally, at the conclusion of the previous robustness based on the mechanical design , Put forward a robust design method based on the quality loss function and practical processi ng technology ,and apply optimization function of the optimal toolbox of MATLAB, as cantilever beam for example to calculate.