In order to evaluate the uniform of SiCp reinforced aluminum metal-matrix composites (MMC) fabricated by powder metallurgy, the ultrasonic velocity imaging was carried out with the method of thickness independent reflector plate (TIRP). Ultrasonic velocity in MMC can be used to calculate the stiffness constants and Yang’s modulus, which are influenced by the volume percentage of SiCp. The TIRP ...

Original scientific paper Stress measurement by using ultrasonic waves is based on acoustoelasticity law, i. e. the relation between stress and wave velocity in engineering materials. Longitudinal critically refracted (LCR) wave is a popular ultrasonic wave in the ultrasonic stress measurement application. The LCR wave is a bulk longitudinal wave that travels within an effective depth underneat...

number of NDE applications. To excite Lamb waves, Ultrasonic Lamb wave techniques are widely used in a mode conversion of bulk waves or photo acoustic excitation are often used. Both of these approaches suffer from the need for liquid couplant or ablation of materials to reach good signal to noise ratio. In this paper, we propose a novel technique that utilizes point source excitation and detec...

A flat transducer was constructed, using a 9-microm-thick PVDF (polyvinylidene fluoride) film for generation and detection of high-frequency ultrasonic waves, and used for measurements of the phase velocity of longitudinal waves traveling along the thickness direction in a very thin material. The transducer has a useful wideband frequency characteristic extending from 10 MHz to over 150 MHz. Me...

Ultrasonic time of flight measurements have been used to estimate the interior temperature of propulsion systems remotely. All that is needed is acoustic access to the boundary in question and a suitable model for the heat transfer along the path of the pulse train. The interior temperature is then deduced from a change in the time of flight and the temperature dependent velocity factor, which ...

This paper presents measurements of sound velocity and attenuation in olive oil, with known chemical composition, as a function of pressure, within the range of pressure up to 0.7 GPa. Dependencies of sound velocity, relative ultrasonic wave attenuation, volume, and adiabatic compressibility on pressure show discontinuities. This proves the existence of the first order phase transition in olive...

Abstract Anisotropy level of human skin is typically obtained by multi-axial tensile test, cutometry, elastography, ultrasonic imaging, etc. Most of the methods are time-consuming, expensive, or not suitable for in-vivo measurements. In this paper a new easily-applicable method for immediate evaluation of human skin local anisotropy is described. Results in this area are of great interest in de...