Dynamics-based Nondestructive Structural Monitoring Techniques.

摘要

A novel Ultrasonic Modal Analysis Technique (UMAT) capable of damage detection in 3-dimensional, non-homogeneous, anisotropic structures based on ultrasonic vibration signatures was developed and implemented into a portable inspection system. The system contains an annular array actuator that is capable of providing various guided wave modes and frequencies as the loading functions to achieve high sensitivity to different defects. An analytical theory on guided wave excitations by annular arrays with/without time delays was developed. The theory can be applied for optimizing annular array designs for UMAT and also conventional transient ultrasonic guided wave applications.