Thermo-acoustic fatigue characterization

Damage mechanism of a nodular cast iron under the very high cycle fatigue regime

“…To calculate the number of cycles to initiate a fatigue crack from an inclusion, several models are used more or less successfully. In the Gigacycle fatigue range, the integration of Paris' law (Xue et al, 2006a(Xue et al, ,b, 2005Puskar, 1977;Luong, 1998Luong, , 1995Bayraktar et al, 2006Bayraktar et al, , 2004Xue, 2005;Garcia et al, 2006;Audenino et al, 2003;Wang, 1998;Meyendorf et al, 2002) allows to predict the number of cycles in the fish eye and obtain the crack initiation number of cycles. The crack initiation stage in the very high cycle fatigue can generally be described in terms of a local micro structurally irreversible portion of the cumulative plastic strain.…”

“…Fig. 7 shows the results of temperature distribution in the gage length section of another cast iron specimen with the similar physical properties and chemical composition (Xue, 2005;Audenino et al, 2003;Wang, 1998;Bayraktar et al, 2004;Meyendorf et al, 2002).…”

<title>Thermography detection of damage initiation during fatigue tests</title>

“…A few laboratories have been working on the feasibility of infrared thermography for this problem for nearly ten years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] . The initially proposed methods are based on the measurement of energy dissipation.…”

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

“…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]. Among these different activities having been published, the parameters commonly used to describe the change in temperature of defined measurement areas are [3,4,6], [5] or [12], which are given different physical meanings by different authors while the symbols being similar.…”

“…Ummenhofer [11] derives a non-linear temperature amplitude with NUC (non-uniformity-correction)-method. Meyendorf and Rösner [21,25] subtract a reference temperature from the average temperature progress during fatigue loading and define and its change for each cycle as damage relevant indicators. When taking thermodynamics during a fatigue process into account it seems to be more reasonable to analyse the temperature progress of the fatigue specimen considering the combination of the first and the second law of thermodynamics.…”