In-situ fatigue life analysis by modal acoustic emission, direct current potential drop and digital image correlation for steel

•Implementation of Acoustic Emission (AE) to understand source and location of crack.•Use of NDT techniques like DCPD and DIC to assist in interpreting AE.•The AE, DCPD and DIC techniques showed good correlation for detecting the damage.•Relatively accurate location of the AE events using times of arrival data.•The waveform and frequency analysis of the AE events aided in discerning at least the two distinct types of crack present. Optimizing acoustic emission (AE) is useful to understand fatigue crack growth of metal structures. Experimental investigation of fatigue in steel with an edge notch was performed using AE to understand source and location of crack formation and growth. Non-Destructive Techniques like Direct Current Potential Drop (DCPD) and Digital Image Correlation (DIC) are useful in assisting to interpret the AE. The cumulation of AE correlated well with the initiation and propagation similar to potential drop values and DIC strain field. 2D AE source location technique was successfully implemented to monitor crack growth. Frequency content correlate with the mode of crack growth.