s-n curve การใช้

• S - n curve movement - based life analytical model
• This model offers a new and simple method for measuring s - n curve and fatigue limit of a material or a machine part
• The relations consist of the survival probability ( p ) - s - n curves , the confidence ( c ) - s - n curves , and the p - c - s - n curves
• According to this model , the s - n curve of a material can be measured with much less samples than before
• Adopting the method in this dissertation to obtain s - n curve can reduce fatigue experiments and helpful in gaining economic efficiency
• P - s - n curve can be obtained by predicting s - n curve and adding to a few fatigue tests . these methods can be reference for engineering application
• The method to obtain a s - n curve is a cost and difficult work , statistic is applied very much . . the bending moment is representation of fatigue value in test
• One point method , mean square curve method and the maximum likelihood principle to predict p - s - n curve for welded steel structures for arbitary survival rate are presented
• Based on the predicting model of effective stress concentration factor , estimating methods of s - n curve for welded steel structures are set up under symmetrical and unsymmetrical stress cycle respectively
• It is feasible to predict the fatigue life of the structure in the critical location when the s - n curve of the fatigue life applied . the meanings and conclusions can effectively instruct the design of leaf spring system
• This paper measures the probability fatigue life of steel wh530 and steel wh6 1 odl which come from wuhan steel and iron company and make out their p - s - n curve based on the basic principle of probability fatigue
• 5 component fatigue life curve ( p - s - n curve ) is used in fatigue life analysis . the thesis provides fatigue life whose possibility is 95 % or 50 % . the analysis results of fatigue life and weak elements agree with fact
• Study the broad sense description and the estimation of the equation parameter of p - s - n curve . study the estimation method of the reliability range of the materials fatigue life under given reliability correspond to different stress level
• The s - n curve , the mathematical relationship of bend fatigue strength or life to strengthening loads and strengthening cycles , the maximum increments of fatigue strength and life were obtained by experimental digital processing
• All experiments were completed by use of loading equipment designed by myself . this equipment has been proved to be efficient , steady and the test data are reliable . based on analysis of the 58 data and 35 domestic data , we got the s - n curve in general use , and established the design method of fatigue
• ( 3 ) the equivalent stress , which is from the coefficients for the spectrum - loads and miner linear accumulated damage rule , an approach for material probabilistic fatigue strength for spectrum loads is suggested . this approach are established by the composed of p - c - s - n curves for extreme maximum model
• The effects are on the probabilistic assessment of both scattering regularity and sampling size of the test s - n data . p - s - n curves are characterized by the scale and location parameters related s - n relations for the maximum value model . the materials constants of in the scale relations are given by the average s - n relations and the locations
• Using the s - n curve , and considering the influence on fatigue characteristics of the leaf spring real feature , we edited the calculation program in ansys postprocessor to calculate the fatigue life on the critical points of leaf spring . at last the result ' s validation was proven by the fatigue test of leaf spring
• On the basis of a reliable finite element model , the load spectrum as specified in aar standard and the s - n curve database for welding joints , regarding the new type of heavy haul open top wagon as the analysis object , fatigue life prediction is conducted in the design phase
• In first part of the thesis , by a review of the research on aircraft sonic fatigue , the formulas for calculating natural frequencies of the typical aircraft skin - panel structure with four edges simply - supported or four edges fixed - supported were drawn , the response of displacement and stress was analysed under the condition of random white noise loading with the steady - state or unsteady - state . the procedure how to use data of s - n curve under constant loading for predicating the fatigue life of skin - panel subjected to random loading was shown