Investigating the spatial focusing performance of time reversal Lamb
waves on a rectangular plate
Jeong Hee Choi
Researches using time reversal acoustics (TRA) for structural health monitoring(SHM) applications have been paied attention to recently. Dispersion characteristics of Lamb waves, which restrict the utility of classical nondestructive evaluation based on time-of-flight information, can be compensated through the application of TRA to Lamb waves on a plate. This study investigates the spatial focusing performance of time reversal Lamb waves on a rectangular plate using finte element analysis. In particular, the virtual sensor effect caused by multiple wave reflections at the boundaries of the plate is shown to enable the spatial focusing of Lamb waves though a very small number of surface-bonded piezoelectric (PZT) sensors are available. The time window size of forward reseponse signals, the center driving frequency, and the number of PZT sensors are normalized with respect to the number of virtuall active sensors. Then their effects on the spatial focusing performance of Lamb waves are investatigated.
Time reversal acoustics, Time reversal Lamb waves, Spatial focusing performance, Active virtual sensor, Finite element method, Pizeoelectirc (PZT) transducers, Structural health monitoring (SHM), Plate