Showing papers in "Wave Motion in 1988"

TL;DR: The basis and applications of the finite-difference time -domain (FD-TD) numerical modeling approach for Maxwell's equations are reviewed, providing highly accurate modeling predictions for a wide variety of electromagnetic wave interaction problems.

TL;DR: In this article, a matrix method is presented for the solution of wave propagation problems in multilayered anisotropic media subjected to time harmonic disturbances, which leads to stable numerical schemes for the evaluation of the displacement and stress fields within the laminate.

TL;DR: In this article, a simple self-consistent embedding scheme is developed for the approximate analysis of waves in a composite consisting of a matrix containing inclusions, which allows the development of simple explicit equations, comparable with those already known for elastostatics.

TL;DR: In this article, a rigorous theory is given, and the development is in the time domain, and probabilistic concepts, such as ensemble averages, are not used; spatial averages suffice.

TL;DR: A modified finite-volume method, which is a direct generalization of the standard finite-difference method to arbitrary polygonal grids, is shown to be the most accurate.

TL;DR: There is no single algorithm that provides an efficient solution for all types of problems in the conjugate gradient method, according to the principal conclusion.

TL;DR: In this article, effective plane-wave propagation, both longitudinal and shear, through a medium containing a random distribution of spherical inclusions is considered, where the particles and matrix are separated by a thin layer of elastic material with different properties.

TL;DR: In this article, a modification to the Stokes' perturbation expansion was proposed to cope with the type of resonance that occurs when two different wavenumbers have identical phase speeds.

TL;DR: In this article, the authors discuss travelling wave solutions of the Kuramoto-Sivashinsky equation and identify three categories of regular shocks, solitary waves, and oscillatory shocks, and present numerical results which indicate the existence of complicated families of solutions.

TL;DR: In this paper, the reflection and transmission of a longitudinal wave by a periodic array of inclined two-dimensional cracks has been investigated, and a pair of singular integral equations has been derived for the crack-opening displacements.

TL;DR: In this paper, the authors discuss numerical modeling of electromagnetic wave scattering and interaction by general arbitrary-shaped two-and three-dimensional material objects in free space based on the frequency-domain integral equation method.

TL;DR: In this article, a geometrical theory of diffraction was proposed to predict the crack-opening displacements associated with the scattering of waves by a crack in a homogeneous, isotropic, linearly elastic medium.

TL;DR: In this paper, specific features in the propagation of thermo-elastic Rayleigh waves are considered and appropriate criteria for behaviour at infinity are discussed in order to preserve the most characteristic features of the Rayleigh wave known from classical elasticity.

TL;DR: In this article, a Rayleigh surface wave by a surface-breaking crack is investigated, where the crack is inclined under an arbitrary angle with the normal to the free surface of a half-space.

TL;DR: In this article, the generalized concepts of Doppler factor, local frequency, wave invariant and group velocity were introduced on the basis of the acoustic energy equation, which can be derived from a variational principle.

TL;DR: In this article, the time domain reciprocity theorems of the time convolution and the time correlation type for elastodynamic wave fields in linear, time-invariant, and locally reacting solids are discussed.

TL;DR: In this paper, a general approach to TLM through transmission-line graphs is presented, and how the theory is applied to electromagnetics through a brief review of methods and applications.

TL;DR: In this article, the linear stability of plane wave solutions of various systems of nonlinear partial differential equations is treated, including an equation for the envelope of a surface wave train on deep water, Zakharov's system for Langmuir waves in plasmas, coupled Schrodinger and Klein-Gordon equations for nucleon and meson fields, and a pair coupledSchrodinger equations.

TL;DR: In this paper, the authors study the inverse problem of determining the impedance of a one-dimensional medium from reflection data which are band-limited and uncalibrated, and show that if we are given, in addition to the reflection data, some a priori information about the impedance, we can in principle determine the desired unknown.

TL;DR: In this paper, the problem of scattering plane waves off a reactively loaded sphere is studied by using the on-surface radiation condition method, which relates the surface pressure and velocity by a linear partial differential equation.

TL;DR: In this paper, it has been shown that the field formation region in the neighbourhood of a stationary saddle point is almost similar to that for an elliptic stationary point, and the analysis of the ray localization process using simple (rectangular, rhombic, or elliptic) shaped holes or with a Gaussian window has been made on the strength of measures suggested in this paper.

TL;DR: In this article, the reflection and transmission tensors associated with a plane elastic wave impinging obliquely upon a stratified slab interposed between two homogenous half-spaces were derived.

TL;DR: In this article, the concept of step shock for a system of conservation laws is introduced, which generalizes the plane constant shock solution to the propagation into a slowly varying medium and to the multi-dimensional case.

TL;DR: In this article, the Green's function for the Helmholtz equation with a constant index of refraction was used to find an integral equation for a class of boundary value problems that arises in inverse scattering problems.

TL;DR: In this article, a perturbation procedure involving strained coordinates combined with the inner and outer expansions is developed to solve such an exterior problem, and analytical expressions for the maximum run-up at the beach and the time when it is attained are presented.

TL;DR: In this article, the steady state scattering of waves by a crack of finite width is considered and formal expressions for the large wavenumber expansion of the crack opening displacements are given.

TL;DR: In this article, it was shown that the wave equation has two kinds of focus wave mode solutions with infinite energy: the splash wave solutions defined as a weighted superposition of the focus wave modes may have a finite energy.

TL;DR: In this article, the reflection of a monochromatic acoustic plane wave from ocean sedimentary layers is considered in the context of a one-dimensional refractive, randomly stratified and dissipative multilayer model.

TL;DR: In this article, exact solutions for model equations that are customarily used to describe resonant and non-resonant wave interactions in non-conservative systems are presented for the case of singularities.