Damage Identification in Plate and Shell Structures by Trilateration Method using Lamb Waves

摘要

A two-stage algorithm that detects and locates damages in thin walled structures using Lamb wave signals is proposed. Isotropic plate and shell structures with adhesively bonded piezoelectric transducers in circular and rectangular array patterns are considered. Lamb waves are generated and sensed by these transducers in pitch-catch mode, before and after making damages in the structure-under-test for baseline subtraction. In the damage identification process, first the correlation coefficient is determined using current and baseline signals. Further, the Trilateration method is adopted to locate the damage using parameters like Time-of-Flight and Group velocity from the damage-scattered Lamb wave signals.