Parameter C lifetime calculation for the high cycle regime

Abstract

An analytical fatigue lifetime prediction using the nominal stress concept and the Palmgren‐Miner‐Rule is performed. A comparison of prediction and experiment shows a large uncertainty. Miner‐Rule modifications have been developed to improve the fatigue lifetime prediction. Stress amplitudes below the fatigue limit are assumed to contribute to the damage at different ratings. The modifications have a significant influence on the predicted fatigue lifetime especially in the high cycle regime. When the maximum stress value is just above the fatigue limit, this influence is most significant. Because there are not many test results of variable amplitude loads available for the high cycle regime, a verification is difficult. In the present paper a new modification for the lifetime prediction is applied. The modification was introduced in 1988 by Hück and suggests a variable slope of a reference S–N‐curve for the damage accumulation. A parameter C and the relation between the maximum stress value of the load spectrum distribution and the fatigue limit determine the slope of the reference S–N curve. The aim is to characterize the influence factors of the parameter C using test results for the high cycle regime achieved on a new test facility and from published test data. This would lead to an improvement of the lifetime prediction in the high cycle regime.

Experimental study on very high cycle fatigue of martensitic steel of 2Cr13 under corrosive environment

“…The very high cycle fatigue phenomenon was originally observed in high strength alloys and surface hardening materials in which crack initiates from subsurface and internal inclusions or microstructural inhomogeneity. Subsequently, a large number of work was reported on very high cycle fatigue in terms of fatigue crack initiation and failure mechanism, typical characteristics, effect affecting very high cycle fatigue behaviour such as frequency, materials strength and life prediction methods …”

“…Subsequently, a large number of work was reported on very high cycle fatigue in terms of fatigue crack initiation and failure mechanism, [13][14][15][16][17] typical characteristics, 9,18 effect affecting very high cycle fatigue behaviour such as frequency, [19][20][21][22] materials strength 19,23 and life prediction methods. 3,24,25 Two questions should be answered in very high cycle fatigue region. One is that because structures continue to fail at very high cycle of over 10 8 cycles, does not a fatigue limit exist at very high cycle fatigue?…”

High-Cycle Microscopic Severe Corrosion Fatigue Behavior and Life Prediction of 25CrMo Steel Used in Railway Axles

“…Accidents involving engineering components are not completely understood. In the past decades, a number of researchers studied the fatigue crack initiation and failure mechanisms [11,12] for very-high-cycle fatigue (VHCF) using fatigue life prediction methods [7,13] to avoid such accidents. For example, Li and Akid proposed a corrosion fatigue model including the stages of pitting and the pit-to-crack transition in order to predict the fatigue life of a structural material and the model showed good agreement with the experimental data at lower stress levels but predicted more conservative lifetimes as the stress increases [14].…”

High-Cycle Microscopic Corrosion Fatigue Behavior and Life Prediction of 25CrMo Steel Used in Railway Axle

“…Accidents involving engineering components are not completely understood. In the past decades, a number of researchers studied the fatigue crack initiation and failure mechanisms [7,8] for very-high-cycle fatigue (VHCF) using fatigue life prediction methods [3,9] to avoid such accidents. For example, Akid R. et al proposed a corrosion fatigue model including the stages of pitting and the pit-to-crack transition in order to predict the fatigue life of a structural material and the model showed good agreement with the experimental data at lower stress levels but predicted more conservative lifetimes as the stress increases [10].…”