Weighted error criterion to evaluate strain–fatigue life prediction methods

Experimental determination of strain–fatigue life curve is expensive considering the time and effort involved. Several empirical relations based on monotonic tensile properties and/or hardness is available for estimating strain–fatigue life properties. Existing criteria to evaluate the accuracy of these empirical relations are limited by the data points in the strain–fatigue life curve. A new criterion based on the prediction errors of fatigue constants is proposed to overcome the limitation. Around eight prediction methods are evaluated for two hundred twenty-six steel grades from literature using the existing and the proposed criteria. It is observed that the conclusions from the new criterion are more reliable than the existing criteria.