The accurate and reliable numerical approximation of the hyperbolic wave equation is of fundamental importance to the simulation of acoustic, electromagnetic and elastic wave propagation phenomena. Here, we present families of variational space–time discretisation methods of higher order for the acoustic wave equation as a protoype model for the three-dimensional elastic wave equation. In tempo...

The scope of this study is to relate the acoustic activity of damage in composites to the failure mechanisms associated with these materials. Cross ply fiber reinforced composites were subjected to tensile loading with recording of their acoustic activity. Acoustic emission (AE) parameters were employed to monitor the transition of the damage mechanism from transverse cracking (mode I) to delam...

In this paper, a wave propagation model is developed to investigate the wave propagation in fluid-filled steel pipe. Based on the Kennard shell equations the investigation is achieved under the conditions of coupling between the shell elastic acoustic field and the interior fluid acoustic field. Tests are conducted on fluid-filled pipeline blockage detection. An active acoustic source is used t...

A large, flat ultrasonic transmitter and a small receiver are developed for studies of material properties in acoustic transmission goniometry. While the character of the wave field produced by the transmitter can be considered as a plane wave as observed by the receiver, diffraction effects are noticeable near critical angles and result in the appearance of weak but detectable arrivals. Transm...

The propagation of both surface and flexural acoustic plate modes along y-rotated x-propagation GaPO4 piezoelectric substrates was studied for several y-cut angles: the phase velocity and coupling coefficient dispersion curves were theoretically calculated for two different electroacoustic coupling configurations. The investigation of the acoustic field profile across the plate thickness reveal...

Thermocline layer have remarkable effects on acoustic propagation in Persian Gulf environment. So far, no comprehensive research has been conducted to explore thermocline layer, especially its characteristics including top, thickness, and thermal gradient of thermocline in Persian Gulf. Besides, effects of thermocline on underwater acoustic propagation including transmission loss and sound chan...

Acoustic wave propagation and attenuation in catalytic converters are investigated in the present study. The relationships for wave propagation in a catalytic monolith are derived first and then coupled to the wave propagation in tapered ducts which are commonly placed at either end of the monolith. Analytical and finite element approaches are used to solve the resulting coupled system of equat...

required. These basic properties of the soil can then be evaluated to assess the acoustic imaging tradeoffs for The potential application of this work is the detection and imaging detecting and characterizing buried artifacts. The acousof buried objects using acoustic methodology. To image buried artifacts, it is vital to know speed and attenuation of sound in the particular tic attenuation coe...