Purpose: The purpose of this paper was to find relationship between the degree of strength degradation caused by fatigue and the changes of ultrasonic wave characteristics such as wave velocity and damping coefficient. Design/methodology/approach: Epoxy-glass composites were subjected to oscillatory bending loadings with constant deflection. During fatigue procedure the force needed to achieve ...

Attached ultrasonic sensors can detect changes caused by crack initiation and growth if the wave path is directed through the area of critical crack formation. Dynamics of cracks opening and closing under load cause nonlinear modulation of received ultrasonic signals, enabling small cracks to be detected by stationary sensors. A methodology is presented based upon the behavior of ultrasonic sig...

In this paper, ultrasonic wave propagation in three phases (3P) of composite materials was investigated. The simulation was conducted by PZFlex analysis code, a time domain finite element program. The reflection and transmission characteristics with different shapes of middle layer between glass fiber and epoxy resin are investigated in order to understand basic ultrasonic behavior of energy di...

A measurement method is described here using a waveguide based technique with special modifications to the end of the waveguide in order to obtain reliable reflected ultrasonic signals from the end of the waveguide that is inside a heating chamber. The interpretation of the reflected signals leading to a quantitative measurement of moduli of the waveguide material i.e. Young‟s (E) and shear (G)...

Ultrasonic guided wave methods are being widely explored for inspection of large structural areas using a sparse array of surface-mounted transducers. However, structural health monitoring (SHM) with guided waves can be problematic because variable operational conditions can significantly affect the measured ultrasonic signals. Although homogeneous temperature variations have been well-research...

The use of piezoelectric wafer active sensors (PWAS) for embedded ultrasonic nondestructive evaluation (NDE) is described. PWAS structure and principle of operation are presented. The interaction between PWAS and ultrasonic Lamb waves is modeled and analyzed, and excitation “sweet spots” for preferentially exciting certain Lamb wave modes are identified. Recent trends in guided-wave ultrasonic ...

Ultrasonic waves form a useful nondestructive evaluation (NDE) probe for determining physical, microstructural, and mechanical properties of materials and parts. Noncontacting laser ultrasonic methods are desired for remote measurements and on-line manufacture process monitoring. Researchers at the Idaho National Engineering & Environmental Laboratory (INEEL) have developed a versatile new meth...

Ultrasound technology was used to analyse the freezing behaviour of orange juice. The ultrasonic properties of orange juice, specifically velocity and attenuation coefficient, were characterised as the temperature was decreased from 20 to −50 ◦C. The results were compared with NMR free induction decay data and correlated with the amount of unfrozen water present in the frozen sample. The veloci...

An ultrasonic guided wave system for pipe inspection is proposed. Using guided wave experience to date on a variety of different tubing problems, feasibility experiments have already been conducted on piping under insulation in both a laboratory and chemical processing facility field environment. Several guided wave techniques are introduced, one using a broad banded variable angle beam transdu...

A lead bismuth eutectic (LBE) spallation target will be installed in the Target Test Facility (TEF-T) in the Japan Proton Accelerator Research Complex (J-PARC). The spallation target vessel filled with LBE is made of type 316L stainless steel. However, various damages, such as erosion/corrosion damage and liquid metal embrittlement caused by contact with flowing LBE at high temperature, and irr...