Influence of Loading Conditions during Tensile Testing on Acoustic Emission

Abstract

The Acoustic Emission (AE) monitoring technique is widely used in mechanical and material research for detection of plastic deformation, fracture initiation and crack growth. However, the influence of AE features (such as signal amplitude, frequency, rise time and duration) on the fracture parameters (such as brittle or ductile mode of propagation and fracture propagation speed) is not completely understood. In this paper, the effect of loading conditions on fracture behavior was studied using AE monitoring during tensile testing of an aluminum alloy specimen. The fracture development was observed using a high speed video camera and was analyzed using the finite element method. The hardware and software produced by Physical Acoustics Corporation (USA) was used. Variations in AE parameters were analyzed and correlated to the stress-strain curves obtained during testing. It is shown that the strain rate and the presence of a crack (modeled by a notch on the sample), affect the fracture mode (brittle or ductile) and a relative amount of the mode dependent AE signatures.

Acoustic Emission Monitoring of Fracture Tests

“…Fracture tests were carried out to detect AE signals associated with crack initiations [27,28,30] and crack growth in metals [29,[31][32][33]. .…”

Investigation of X80 Line Pipe Steel Fracture during Tensile Testing Using Acoustic Emission Monitoring

“…Mukhopadhya et al [4] studied AE generated by the dislocation movement in an austenitic stainless steel sample. Chuluunbat at al [5] investigated the effect of loading conditions on fracture behaviour of aluminium alloy using AE monitoring during tensile testing. Yusof at al [6] studied AE activity of X70 pipeline steel subjected to fatigue.…”

Source Identification and Classification of Acoustic Emission Signals by a SHAZAM-inspired Pattern Recognition Algorithm

“…In a subsequent work, T. Boczar studied the dominant frequencies of Hsu-Nielsen sources, observing a wide frequency range for this type of AE pulses [9]. Spectrogram analysis of acoustic signals was also successfully employed for fault diagnosis and condition monitoring of internal combustion engines [7].…”

“…This methodology confirmed the effectiveness of cluster analysis on frequency content of AE signals for damage characterization. Finally, T. Chuluunbat combined waveform and power spectrum analysis to correlate AE activity and damage mechanisms during tensile testing of aluminum alloy specimens [9]. Damage types were classified depending on the amplitude and frequency peak of the FFT power spectrum derived from AE.…”