The paper presentsan ultrasonic guided wave methodology for inspection of a fillet joint with a bend.Owing to the complex shape of the geometry, it is not amenable for conventional techniques. The methodology developed utilizes through-transmission ultrasonic testing. Two 90Δ angle beam (surface wave) ultrasonic transducers of central frequency 2.25 MHz, acting as a transmitter and a receiver a...

all experiments in this study were carried out in a flume which was located in the hydraulic laboratory of technical faculty in guilan university. the wave flume was 12 m long, 0.5 m wide, 0.5 m high and equipped with a wave-producing system and ultrasonic sensors. the objectives of current experimental study are to investigate sediment transport, bed formation and sustainability of sandy beach...

A novel ultrasonic dispersion system for the dispersing of particles which are mixed in liquid has been proposed in this paper. The frequency of produced ultrasonic wave varies from 30 kHz to 60 kHz with 100 Hz steps. It means that the operating frequency band of designed system is 30 kHz. The maximum and optimum energy of ultrasonic wave can be transfer inside the liquid container with the hig...

There are many advantages to adhesively bonding stiffeners onto aircraft structures rather than using traditional mechanical fastening methods. However there is a lack of confidence of the structural integrity of adhesively bonded joints over time. Acousto-ultrasonic Lamb waves have shown great potential in structural health monitoring applications in both metallic and composite structures. Thi...

The laser-ultrasonic technique is proposed for defect detection and residual stress measurement in friction stir welds (FSW). When combined with the synthetic aperture focusing technique (F-SAFT), very good performances are achieved for detecting lack of penetration in butt joints, the detection limit coinciding with the conditions of reduced mechanical properties. Also, the detection of kissin...

The longitudinal acoustic velocity in silica aerogel is presented as a function of the interstitial gas type and pressure. This was measured using air-coupled ultrasonic transducers configured for differential pulse transit time measurements. The results are interpreted in terms of the thermal relaxation of the acoustic pulse. The microscale temperature oscillations of the gas and solid phases ...

Air-coupled ultrasonic inspection using leaky Lamb waves offers attractive possibilities for non-contact testing of plate materials and structures. A common method uses an air-coupled pitch-catch configuration, which comprises a transmitter and a receiver positioned at oblique angles to a thin plate. It is well known that the angle of incidence of the ultrasonic bulk wave in the air can be used...

This study identified depths of artificial pitting corrosion on the galvanized steel wires, frequently used in bridge cables, based on the time reversal method (TRM). Specifically, the multimode longitudinal ultrasonic guided waves are excited in terms of characteristics of radical distribution of the normalized average energy flow density (NAPFD) in a wire. Furthermore, the complex defect scat...

An ultrasonic wave propagating through a microscopically inhomogeneous medium, such as polycrystalline materials, is subject to scattering at the grain boundaries as well as other inhomogenities. The fraction of energy removed from the incident wave is responsible for important phenomenon like attenuation, dispersion, and background “noise" associated with a given ultrasonic inspection system. ...