Acoustic Emission multiplets during fatigue of aluminum
A series of uniaxial low cycle fatigue tests on pure Aluminum is investigated via the analysis of acoustic emission (AE).The different stages of macroscopic fatigue behavior are clearly differentiated in terms of AE.We define five different stages: initial hardening,initial softening,secondary hardening during shakedown stage,onset of secondary softening and failure.When most of the acoustic activity recorded in the two/three first stages is related to dislocation dynamics,the acoustic activity in the last stages is mostly due to the fracture phenomenon.Now,a detailed analysis of the discrete AE allowed to highlight the appearance,in the last third of the test,of acoustic signals occurring almost every cycle at a same given stress and having a quasi identical acoustic signature.We hypothesize that such multiplets,shown for the first time in acoustic emission,are the signature of the propagation,cycle after cycle,of a fatigue crack whose trace may be seen post-mortem with the fatigue striations on a fracture surface.This way,these signals could be considered as fracture precursors about several hundred cycles before the final failure of the material.
Acoustic Emission Fatigue Fracturing process AE multiplet Cracks
Wafa Ben Rhouma Stéphanie Deschanel Jér(O)me Weiss
Université de Lyon,INSA-Lyon,MATEIS,CNRS UMR 5510,F-69621 Villeurbanne,France;LGGE,CNRS,UJF-Grenoble Université de Lyon,INSA-Lyon,MATEIS,CNRS UMR 5510,F-69621 Villeurbanne,France LGGE,CNRS,UJF-Grenoble,38402 St Martin dHérès,France
国际会议
北京
英文
1-7
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）