In this paper, we consider the generalized linear solid model of viscoelastic wave propagation, which is modeled by a system of integro-differential equations. We show the existence and uniqueness of a weak solution to the initial-boundary value problem; we show that the solution has finite propagation speed; and we prove regularity results for the solution, depending on the regularity of the d...

The aim of this paper is to discuss simulation methods of diffraction of electromagnetic waves on biperiodic structures. The region with complicated structures is discretised by Nédélec Finite Elements. In the unbounded homogeneous regions above and below, a plane wave expansion containing the exact far-field pattern is applied. A consistent coupling is achieved by the method of Nitsche. By num...

By linearity, the above two questions are reduced to the unique continuation property (UCP) for the wave equation. Due to finite speed of propagation, the (UCP) holds only for T > 0 large enough and Ω will be supposed a connected domain. For instance, for a sufficiently smooth boundary, if T > 2max { dist (x, Γ) , x ∈ Ω}, then by Holmgren uniqueness theorem N = {u ∈ H (Ω× (0, T )) being a solut...

We consider front tracking approximate solutions to the p-system of isentropic gas dynamics. At interaction times, the outgoing wave fronts have the same strength as in the exact solution of the Riemann problem, but some error is allowed in their speed. For large BV initial data, we construct examples showing that the total variation of these approximate solutions can become arbitrarily large, ...

This paper deals with entire solutions of a bistable reaction-diffusion equation for which the speed of the traveling wave connecting two constant stable equilibria is zero. Entire solutions which behave as two traveling fronts approaching, with super-slow speeds, from opposite directions and annihilating in a finite time are constructed by using a quasiinvariant manifold approach. Such solutio...

in this paper, the propagation of the waves in the laminated composite plates which is subjected to low velocity impact is investigated using the finite element method. a rigid metallic projectile with spherical nose is considered and the impact of this projectile with laminated composite is studied in this study. considering a finite element model the governing equations of the problem is disc...

This paper analyzes the adequacy of shell models for predicting stresses and strains in thick-walled tubes subjected to detonation loads. Of particular interest are the large axial strains which are produced at the inner and outer surfaces of the tube due to bending along the tube axis. First, comparisons between simple shell theory and a static finite element model are used to show that the ax...

An approximation technique is considered for computing transmission and reflection coefficients for propagation of an elastic pulse through a planar slab of finite width. The propagation of elastic pulse through a planar slab is derived from first principles using straightforward time-dependent method. The paper ends with calculations of enhancement factor for the elastic plane wave and it is s...