Rapid Estimation of Mean Value and Standard Deviation of Endurance Limit Using Acoustic Emission

Abstract

The behavior of AE total ringdown counts during the stepwise increment of oscillating stress under various conditions (loads, microstructures and materials) was investigated and the following conclusions were obtained.
1) Various factors influencing AE total ringdown counts during the stepwise increment of oscillating stress were clarified.
2) The mean value and standard deviation of stress giving rapid AE increment corresponded to those of the endurance limit given by 14S-N testing method under various conditions (loads, microstructures and materials). Thus, the mean value and standard deviation of the endurance limit can be estimated precisely from the stress giving rapid AE increment.
3) The stress giving rapid AE increment corresponded to generation of slip bands during the stepwise increment of oscillating stress. It was 0.9 times of the endurance limit given by 14S-N testing method.