Numerical and Experimental Location Detection of Through Defect in Homogenized Plates using Tomography of Surface Wave Method

Abstract

Using surface guided wave is one of the most reliable methods of structural health monitoring. Mostly the bulk wave is preferred for identification of internal defects, which is inefficient in localizing the surface cracks. In this paper the procedure of ultrasonic surface wave tomography for crack detection in an aluminum plate is investigated and applied for three cracks with the length of 4, 7 and 10 milimeters. Analytical equations and numerical simulations are used to extract dispersion curves as a means for selection of plate thickness and piezoelectric characteristics. Layout selection for transducers and providing numerical and experimental models are the next steps of inspection procedure. All the piezoelectric discs are actuated respectively. Meanwhile, other piezoelectric elements are used as sensors and their received signal is stored in both healthy and defected structures for both numerical and experimental models. Definition of signal difference criteria, signal reconstruction and tomogram generation are the last steps of the procedure presented in this paper.

Keywords

• tomography
• guided wave
• fault detection
• surface wave