Estimation of the Fatigue Limit by Progressively-Increasing Load Tests

Abstract

On the basis of fatigue data derived from a large number of experiments, the load progression methods of Locati and Prot as well as a method operating on a thermometric basis have been comparatively evaluated in an experimental and analytical (statistical) study. The last-named thermo-method can provide useful estimates for a fatigue limit corresponding with ca. 0 to 5% probability of fracture with only 1 to 3 experiments.The Prot-method, set up and evaluated in a certain way, provides a useful estimate of the fatigue limit and, additionally, an approximate indication of the width of the transition range of the corresponding Wohler-type tests after experiments on not less than about ten specimens.The load progression, contrary to the original Prot-concept, must not necessarily be applied in a continuous mode, but can occur stepwise with increments Au smaller than ca. 15 N rnm-'.

Corrosion, fatigue and corrosion fatigue behaviour of metal implant materials, especially titanium alloys

“…As mentioned above, temperature measurements are very well suited for characterising fatigue processes [80][81][82]. As compared to single step tests, load increase tests in combination with mechanical hysteresis and temperature measurements offer a good possibility to determine the cyclic yield strength of a material with a very limited number of specimens [80,81,[83][84][85]. The cyclic yield strength represents an estimation value of fatigue strength as has been shown for different steels with ductile microstructures by correlating results of load increase and single step tests [81,84].…”

Analysis of the fatigue strength under two load levels of a stainless steel based on energy dissipation

“…The evaluation of fatigue limit of materials based on the experimental measurements of thermal increments is an experimental procedure well documented in the literature [1][2][3]. Recently one of the Authors suggested to adopt the energy released to the surroundings as heat by a unit volume of material per cycle, Q, as a fatigue damage indicator [4].…”

Characterization of the fatigue behaviour and lifetime evaluation of metallic materials based on thermographic NDT-methods

“…Among the different thermometric methods [3][4][5][6], IR(infrared)-camera-based quantitative thermography has enormous advantages over other methods due to its non-contact feature and surface information to be visualized, which is therefore appropriate to provide more information regarding the fatigue behavior. Since Reifsnider and Williams applied an IR-camera in this field for the first time [7], there is an increasing number of publications dealing with similar methods [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”