

Sensor Location Analysis for Fatigue Crack Detection Using Nonlinear Acoustics
Abstract
Structural Health Monitoring and Non-destructive Testing systems require reliable methods techniques that detect very small defects or indicate changes in structural performance at very early stages of deterioration. Guided ultrasonic waves and ultrasonic methods based on various nonlinear phenomena are often used for earlystage damage detection. The later has attracted many investigations for the last fifteen years. The paper investigates the effect of sensor location for crack detection in metallic structures based on nonlinear vibro-acoustic wave modulations. Surfacebounded, low-profile piezoceramic transducers are used for low- and high-frequency excitations. Ultrasonic responses are monitored using non-contact laser vibrometry. The study reveals plate areas more sensitive to nonlinear wave modulations.