This paper presents a set of analytical and numerical results on the use of guided waves for structural health monitoring application. The aim of the work presented in this paper is to provide tools to extend modeling capacities and improve quality and reliability of guided wave propagation models using commercially available finite element (FE) packages. Predictive simulation of ultrasonic non...

A novel silicon ultrasonic horn with microprobes is developed for surgical applications. During insertion, penetration force of the microprobes driven by the ultrasonic horn can be reduced and tissue damage is minimized. The new horn has a profile of a Bézier curve. The dynamical characteristics of the horn are examined. Microscale prototypes are fabricated. Using the driving technique, the for...

Acoustic microscopy [1] is used to measure the V(Z) curves and thereby determine the ultrasonic velocities on the surfaces of solid materials. The acoustic transducer, pointor line-focusing, is defocused below the sample surface through the coupling water. The focal depth Z is changed to extract the interference between the specular reflection signal and the leaky surface wave signal(s). Their ...

This article reviews some new ultrasonic rail inspection methods emerging in recent years. It focuses on the state of the art for guided wave technologies and their potential use for used for rail inspection. It considers ultrasound transduction options including EMATs, air coupled, pulsed laser and wheel probe guided wave methods. It compares performances in terms of frequency ranges, energy d...

Ultrasonic guided waves are used to detect the delamination between skin and honeycomb of a composite helicopter rotor blade. Theoretical work is carried out for guided waves in the trailing edge of a rotor blade, which is a multilayer composite skin/NOMEX half space structure. The dispersion relation is obtained with the global matrix method. Theoretically driven experiments are conducted on a...

For analyzing partial discharge ultrasonic wave characteristic on typical defects in SF6 gas insulation switchgear (GIS), a 110 kV GIS was taken as an object to design and simulate the typical partial discharge models in GIS There are point electrode model on bus and cavity of GIS, floating electrode model, air interstice model in insulator, metal particle and iron core electromagnetic shock mo...

The broadband narrow pulse self-focusing ultrasonic transducer was designed for the special structure of the column holes, and used to do the research for the testing of bonding layer of metal composite material with F-scan ultrasonic imaging system. The copper-steel boding layer of bimetal rotor is connected by diffusing welding. There may be delamination flaws existed here. The depth and rang...

With increased use of composite materials in critical structural applications it is more important than ever to independently assure structural integrity. Complexity of the advanced composite materials including layered and bonded structures represents challenges in developing optimized ultrasonic tests. Traditional ultrasonic NDT methods are inappropriate and often misleading when applied to a...

Ultrasonic fields in glycerol are visualized by holographic interferometry with a phase-modulated reference beam. Fine particles suspended in glycerol are illuminated with sheetlike light, and the light scattered from the illuminated plane is recorded in a hologram. The ultrasonic field on the plane is displayed in the reconstructed image, which provides equiphase positions of the wave, i.e., w...