Statistical Processing Methods And Software Development Of Material Fatigue And Fracture Mechanics Experimental Data

A full understanding of the metal material is essential in product design of machinery. Fatigue and Fracture are typical damage mechanisms and failure modes in mechanical system and its components, Accordingly, it is significant and applicable to design based on the fatigue behavior and fracture property data.Researches on the statistical methods for data analysis of the metallic material high cycle fatigue and metal fatigue crack growth rate (fracture mechanics) are carried out in this thesis. Main Contents are:The traditional D-M method of lifting test method data is presented here for the fatigue limit of metallic materials. Based on rank distribution theory, improved statistical methods are proposed, including rank distribution-three-parameter Weibull distribution, rank distribution-normal distribution, rank distribution-lognormal distribution. Besides, the solution to the estimation of the fatigue limit under the given confidence and reliability is also provided.Researches on group experiment data statistical processing methods. is carried out for S-N curve for high cycle fatigue. Methods of one-sided tolerance factor and new one-sided tolerance factor are put forward using the two-parameter and three-parameter S-N power function, three-parameter Weibull distribution-rank distribution solving the S-N curve and C-P-S-N curve. is proposed with the consideration of the initial value problem of fatigue limit. In addition, methods on S-N curve or P-S-N curve based on the principle of sample information gathered is brought up for scared sample cases.Solution procedures of the crack growth rate da/dN-AK curve are developed for fatigue crack growth rate. Subsequently, the unilateral tolerance factor method is presented based on. Further, expression for varied non-standard specimens' stress intensity factor range ?K is offered.To expedite and systematize the data process, procedures of statistical methods presented above are programmed as two application software:"The statistical processing software of metal material high cycle fatigue-fatigue limit and S-N curve " and" The calculation software of metallic materials crack growth rate"...