Interrelationship between Stress Intensity Factor and Acoustic Emission Parameter in the Opening Mode Fatigue Crack Propagation

Interrelationship between stress intensity factor and acoustic emission parameter in the opening mode fatigue crack propagation was investigated. Under various conditions with different cyclic amplitudes and crack lengths, counts rate behavior was examined. Experimental results indicated that stress intensity factor range ( K) could be divided into two parts according to its relationship with counts rate. This interrelationship was keeping the same trend regardless of load range or crack length for all tested materials. However, more distinct interrelationship was shown as the material has lower yield strength and higher ductility. Overall experimental data were somewhat scattered since sensitive characteristics of acoustic emission method. However, these empirical relations indicated that AE counts rate was uniquely correlates with single parameter, K.