Structural health monitoring by high-frequency vibration measurement with non-contact laser excitation

Abstract

This paper proposes a vibration testing and health monitoring system based on an impulse response excited by a laser ablation. High power YAG pulse laser is used for producing an ideal impulse force on structural surface. It is possible to measure high frequency vibration responses in this system. A health monitoring system is constructed by this vibration testing system and a damage detecting algorithm. A microscopic damage of structures can be extracted by detecting fluctuations of high frequency vibration response with the present health monitoring system. In this study, loosening of bolt tightening torques is defined as the damage of the system. The damage is detected and identified by statistical evaluations with Recognition-Taguchi method.

Damage detection in membrane structures using non-contact laser excitation and wavelet transformation

“…This allows the conclusion that using laser excitation to excite membrane structure in vibration testing is appropriate, because vibration testing using laser excitation provides the high frequency vibration data [6,[13][14][15][16].…”

Bolt loosening analysis and diagnosis by non-contact laser excitation vibration tests

“…These issues have led to research into non-contact excitation methods with better reproducibility. Vibration measurement systems using non-contact laser excitation can guarantee a very high degree of measurement reproducibility [11][12][13].…”