Novel method for in situ damage monitoring during ultrasonic fatigue testing by the advanced acoustic emission technique

Abstract

Ultrasonic fatigue testing (USFT) is an effective method for the rapid characterisation of the high cycle fatigue properties of structural materials. However, the process of initiation and progression of fatigue damage remains uncertain in this way of testing due to the limitations of existing measuring techniques. The acoustic emission (AE) method was developed in the present work to pave a new way to monitor the fatigue process during USFT. The proposed new methodology revealed the AE activity related to fatigue damage, allowing to distinguish between surface and internal fatigue crack initiation and to follow the development of fatigue damage.