Estimating S–N curves and their scatter using a differential ant-stigmergy algorithm

Multiaxial high-cycle fatigue criteria and life prediction: Application to gas turbine blade

“…Since fatigue test results are widely scattered especially for HCF region, several probabilistic models were available in the literature to estimate the S-N curve considering its scatter [23,24]. In this section, and for each loading configuration, stress life curves were simulated using the Stromeyer, Palmgren and Bastenaire models [25] .…”

Influence of fatigue–life data modelling on the estimated reliability of a structure subjected to a constant-amplitude loading

“…Klemenc and Fajdiga [13] showed that it is possible to estimate the three parameters a 0 , a 1 and β N from the fatigue-life data set S ¼ fðS a;i ; N i Þ; i ¼ 1; …; ng with a differential ant-stigmergy algorithm (DASA), as proposed by Korosec et al [15]. A Windows 7.0 executable file for jointly estimating the trend and the scatter of the N(S a ) curve can be found on the internet -see Klemenc and Fajdiga [16].…”

“…For this reason the scatter of the N (S a ) curve is usually modelled in a direction of the number of cyclesto-failure N with a conditional PDF f ðNj S a Þ. Recently, Klemenc and Fajdiga [13] have developed a procedure for a joint estimation of the N(S a ) curve trend and its scatter. They applied a power-law equation for modelling the N(S a ) curve in the high-cycle fatigue domain.…”

“…Simulated data sets Experimental data set -S420MC steel Number of data points 20, 50, 100, 200, 500 or 1000 79 (65 with a [15] or Klemenc and Fajdiga [13,21]. b For the simulated data sets the processing time figures are valid for the data set with 1000 data points.…”

Probability density function of the equivalent stress amplitude using statistical transformation

“…Fatigue strength of materials is usually given in the form of S-N curves for constant-amplitude loading [3,26]. If only amplitude loading is taken into account, then the number of load cycles to failure is primarily modelled by three statistical distributions: normal, Weibull and log-normal distribution [27,28]. However, mechanical components are usually subjected to cyclic loads in the presence of mean stress [29].…”