Detection and localization of fatigue cracks originating from fastener holes is an important application of proposed systems for structural health monitoring (SHM). However, detection of even large fatigue cracks using ultrasonic guided waves can be challenging when cracks are tightly closed, which is common in the absence of applied tensile loads. It can also be problematic to detect fatigue c...

Guided ultrasonic waves are frequently used for both structural health monitoring and nondestructive testing of metallic plate-like structures. Signals resulting from waves generated by one or more fixed piezoelectric transducers can be recorded around the periphery of an area of interest using a non-contact approach such as a scanning laser vibrometer. It is desired to determine the location o...

This paper studies the acoustic backscattering of short ultrasonic pulses by air-filled stainless steel-solid polymer two-layer cylindrical tubes immersed in water. The stainless steel one-layer tube is taken as a reference. The focus of this paper is on revealing the effects of physical characteristics of the solid polymer on the scattering phenomenon. The work is done from the calculation of ...

Corrosion is a major safety and economic concern to various industries. In this paper, a novel ultrasonic guided wave tomography (GWT) system based on self-designed piezoelectric sensors is presented for on-line corrosion monitoring of large plate-like structures. Accurate thickness reconstruction of corrosion damages is achieved by using the dispersive regimes of selected guided waves and a re...

Ultrasonic sensors permanently affixed to aluminum coupons are used to monitor progression of damage during fatigue testing with the long term goal of structural health monitoring for diagnostics and prognostics. Necessary for success are proper design of the ultrasonic testing methods, robust transducer mounting techniques, and real-time signal processing for determining the state of the struc...

This paper presents OptiSens, a computational platform in Python and Matlab, that provides optimal sensor actuator configurations for structural health monitoring applications using ultrasonic guided-waves. software formulates convex entropy-based objective function, which aims at minimizing the uncertainty while maximizing expected accuracy of system localizing damage. The is specialized two t...

background: the purpose of the present study was to assess the efficiency of ultrasound/hydrogen peroxide processes and ultrasound/hydrogen peroxide/zno nanoparticles in the removal of blue cat 41 dye from aqueous solutions. methods: zno nanoparticles were prepared using the hydrothermal method. variables including ph, concentration of zno nanoparticles, initial dye concentration, concentration...

Piezoelectric transducers have been widely used for the generation and detection of ultrasonic waves for structural health monitoring. Recently, we proposed the use of inductive coupling in order to implement wireless coupling to a Lamb wave transducer. In that transducer the ultrasonic waves were generated by a piezoelectric wafer attached to the surface of a plate. These transducers are effec...