Abstract
This paper proposes a vibration testing and health monitoring system based on an impulse response excited by a laser ablation. In conventional vibration testing using an impulse hammer, the excitation force hardly includes high frequency element over tens of kilohertz. High power YAG pulse laser is used in this system for producing an ideal impulse force on structural surface. It is possible to measure high frequency FRF (Frequency Response Function) in this system. And water droplet overlay on the metal is used to adjust the force magnitude in laser excitation. A health monitoring system is constructed by this vibration testing system and damage detecting filter. A microscopic damage of structures can be extracted by detecting fluctuations of high frequency vibration response with this health monitoring system. The vibration testing system is validated by comparing an aluminum block's FRFs that are obtained by laser excitation, impulse hammer and FEM.
