Probabilistic modeling of unified S-N curves for mechanical parts

Abstract

This article aims at modeling unified S-N curves based on multifailure modes and stress ratios. Heterogeneous mixture distributions are used to describe life distribution of multifailure modes. Bayes clustering is applied to cluster failure data to avoid convergence to global optima. Derived from regression analysis, failure data are compensated by nonrandom error. The relationship between distribution parameters and stress is established, and the ultimately unified probabilistic S-N curve is modeled. Two assumptions are presented to modify an original S-N curve model with varied stress ratios. The first one is to take into account the effects of low-amplitude load “exercising,” which we call results in the “pseudo-fatigue damage.” The other one is to set up probability density function of fatigue limit considering uncertainty. Combined with material parameters modification, thus a new modified and unified S-N curves model is available for not only researchers, but engineers as well.

Fatigue life prediction of clutch sleeve based on abrasion mathematical model in service period

“…The normal distribution curve of asperity heights than 9%, which shows that the approximate Equation (27) in the integral region is reasonable within [h, +∞).…”

“…By calculating the approximate value, the error between the results of Equations (27) and (26) is not more…”

“…25 With the development of material science, chemistry, surface physics, and testing technology, the friction mechanism has also been further studied. 26,27 This provides a theoretical basis for revealing the abrasion law and establishing a better prediction model. On the basis of the method of mathematical modeling, 28 Archard and former Soviet Union scholar Gaiersiji have quantitatively deduced the theory of adhesive abrasion and the theory of fatigue abrasion, which have been widely applied.…”

Using Fatigue Characteristics to Analyse Test Results for 16Mo3 Steel under Tension-Compression and Oscillatory Bending Conditions

“…Moreover, the authors' proposed model (6) is "S"-shaped, which is sometimes recommended for fatigue life models [21], particularly for stress specification. Both Langer and Kandil models are widely used in modern science, for example [22][23][24]. Figures 12 and 13 present a comparison of curves according to all proposed models of tension-compression and oscillatory bending.…”

A time-dependent probabilistic fatigue analysis method considering stochastic loadings and strength degradation

“…1 During the past decades, a number of researchers have sought to calculate the fatigue reliability of mechanical products based on probabilistic methods. These methods can be grossly divided into three categories: fatigue life-based reliability analysis method, [2][3][4] fatigue damage cumulative-based reliability analysis method, 2,[5][6][7][8][9][10][11][12][13][14][15][16] and residual strength degradation-based reliability analysis method. [17][18][19][20] According to crack propagation theory or fatigue cumulative damage theory, the fatigue life-based reliability analysis method considers the fatigue life as the control parameter to estimate fatigue reliability.…”