The method of finite spheres for wave propagation problems

2014 ◽  
Vol 142 ◽  
pp. 1-14 ◽  
Author(s):  
Seounghyun Ham ◽  
Benjamin Lai ◽  
Klaus-Jürgen Bathe
Keyword(s):  
Wave Propagation ◽  
Finite Spheres

scholarly journals The method of finite spheres in acoustic wave propagation through nonhomogeneous media: Inf-sup stability conditions

2020 ◽  
Vol 42 (3) ◽  
pp. 209-237
Author(s):  
Williams L. Nicomedes ◽  
Klaus-Jürgen Bathe ◽  
Fernando J. S. Moreira ◽  
Renato C. Mesquita
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Acoustic Wave Propagation ◽  
Nonhomogeneous Media ◽  
Finite Dimensional ◽  
Pressure Fields ◽  
Time Harmonic ◽  
The Stability ◽  
Finite Spheres ◽  
Well Posed

When the method of finite spheres is used for the solution of time-harmonic acoustic wave propagation problems in nonhomogeneous media, a mixed (or saddle-point) formulation is obtained in which the unknowns are the pressure fields and the Lagrange multiplier fields defined at the interfaces between the regions with distinct material properties. Then certain inf-sup conditions must be satisfied by the discretized spaces in order for the finite-dimensional problems to be well-posed. We discuss in this paper the analysis and use of these conditions. Since the conditions  involve norms of functionals in fractional Sobolev spaces, we derive ‘stronger’ conditions that are simpler in form. These new conditions pave the way for the inf-sup testing, a tool for assessing the stability of the discretized problems.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Simulation of Sound Wave Propagation With Damping for Realistic Sound rendering for Games and Interactive Applications

2012 ◽  
Author(s):  
Bruno Moreira ◽  
Mauricio Kischinhevsky ◽  
Marcelo Zamith ◽  
Esteban Clua ◽  
Diego Brandao
Keyword(s):  
Wave Propagation ◽  
Sound Wave ◽  
Interactive Applications ◽  
Sound Rendering
Sign in / Sign up

Export Citation Format

Share Document