The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to th...

This paper deals with an experimental description of the acoustic behaviour of non-consolidated granular materials submitted to static force. The aim of this work is to investigate the effect of a small amount of an interstitial fluid on the acoustic propagation. Measurements of the velocity and of the transmission of the coherent wave are performed for different values of the applied force. It...

In continuous wave ultrasonic Doppler tomography (DT), the ultrasonic beam moves relative to the scanned object to acquire Doppler-shifted frequency spectra which correspond to cross-range projections of the scattering and reflecting structures within the object. The relative motion can be circular or linear. These data are then backprojected to reconstruct the two-dimensional image of the obje...

The advent of dry point transducers has allowed new possibilities for ultrasonic testing of concrete structures and rock specimens. Recent developments in the technology such as single and multi-channel ultrasonic pulse echo technology and the automated determination of the modulus of elasticity have been pushing back the boundaries of the method. The effect of this has been to increase the eas...

People have difficulty understanding ultrasonic sensing because they cannot see sound. The purpose of simulation is to overcome this problem by visualizing the scattering of ultrasonic waves off objects. The lattice gas model calculates wave behavior with finite difference equations to produce data suitable for grayscale visualization. This visualization is useful when designing ultrasonic sens...

Ultrasonic testing is a versatile and important nondestructive testing method. In many industrial applications, ultrasonic testing is carried out at relatively high temperatures. Since the ultrasonic w...

Due to the problems of dispersion and multi-modes overlap for ultrasonic Lamb wave propagation, it is difficult to use it in many fields, such as long-range inspection. After ultrasonic Lamb waves are generated by a broadband ultrasonic pulse, these problems make the wave packets to spread out and various modes overlap in both time and space domain as they propagate through a plate or pipe. It ...

Introduction Compared to ultrasonic bulk waves that travel in infinite media with no boundary influence, guided waves require a structural boundary for propagation. As an example, some guided wave possibilities are illustrated in Figure 1 for a Rayleigh surface wave, a Lamb wave, and a Stonely wave at an interface between two materials.

Polymer Bonded Explosives (PBX) are well-known explosives for the weapons, especially for the parts of some important weapon. Generally, they first are modelled in cylinder. One of the most important issues in PBX cylinder properties is the detection of its flaw. Each PBX cylinder may have flaws that influence the security, machine-performance and other important physical or chemical performanc...