In this paper, we researched visualization of guided wave propagation in pipe with defect. The characteristic of three-dimensional sound field is simulated by finite element method. First, the characteristics of many modes of guided wave propagation in pipe and the interaction of guided wave with defect is studied. Then, the model of scattering sound field for defect exist is builded when guide...

advantages and disadvantages of using “stokes parameters” in exploration of inertia-gravity wave properties are discussed in this paper. the survey is carried out on an inertia-gravity wave event (igws in what follows) that occurred over iran from 7 to 9 february 2012. applying this technique for investigation of atmospheric igws was recommended by vincent and fritts (1987) and then developed b...

In the present paper, discrete element method (DEM) is used to study wave propagation phenomenon in granular soils. The effect of factors such as coefficient of friction, frequency, normal stiffness and soil gradation on the wave velocity is studied. Using the wall motion based on the sinusoidal function is the method of loading used in this simulation, through which the pressure wave is transf...

A mechanical model representing an acoustic metamaterial that exhibits simultaneously negative mass density and negative Young's modulus was proposed. Wave propagation was studied in the frequency range of double negativity. In view of positive energy flow, it was found that the phase velocity in this range is negative. This phenomenon was also observed using transient wave propagation finite-e...

We investigate the propagation of transverse elastic waves in crumpled media. We set up the wave equation for transverse waves on a generic curved, strained surface via a Langrangian formalism and use this to study the scaling behavior of the dispersion curves near the ridges and on the flat facets. This analysis suggests that ridges act as barriers to wave propagation and that modes in a certa...