The search session has expired. Please query the service again.
The search session has expired. Please query the service again.
Displaying 141 –
160 of
187
Numerical simulation of high frequency waves in highly heterogeneous
media is a challenging problem. Resolving the fine structure of the
wave field typically requires extremely small time steps and spatial
meshes. We show that capturing macroscopic quantities of the wave
field, such as the wave energy density, is achievable with much
coarser discretizations. We obtain such a result using a time
splitting algorithm that solves separately and successively
propagation and scattering in the...
A parabolic system arisng as a viscosity regularization of the quasilinear one-dimensional telegraph equation is considered. The existence of - a priori estimates, independent of viscosity, is shown. The results are achieved by means of generalized invariant regions.
2000 Mathematics Subject Classification: 26A33, 33E12, 33C60, 44A10,
45K05, 74D05,The aim of this tutorial survey is to revisit the basic theory of relaxation
processes governed by linear differential equations of fractional order. The
fractional derivatives are intended both in the Rieamann-Liouville sense
and in the Caputo sense. After giving a necessary outline of the classica
theory of linear viscoelasticity, we contrast these two types of fractiona
derivatives in their ability to take into...
The author investigates time-periodic solutions of the quasilinear beam equation with the help of accelerated convergence methods. Using the Newton iteration scheme, the problem is approximated by a sequence of linear equations solved via the Galerkin method. The derivatiove loss inherent to this kind of problems is compensated by taking advantage of smoothing operators.
The topological asymptotic analysis provides the sensitivity of a given shape functional with respect to an infinitesimal domain perturbation, like the insertion of holes, inclusions, cracks. In this work we present the calculation of the topological derivative for a class of shape functionals associated to the Kirchhoff plate bending problem, when a circular inclusion is introduced at an arbitrary point of the domain. According to the literature, the topological derivative has been fully developed...
The topological asymptotic analysis provides the sensitivity of a given
shape functional with respect to an infinitesimal domain perturbation, like
the insertion of holes, inclusions, cracks. In this work we present the
calculation of the topological derivative for a class of shape functionals
associated to the Kirchhoff plate bending problem, when a circular inclusion
is introduced at an arbitrary point of the domain. According to the
literature, the topological derivative has been fully developed...
This paper deals with the formulation of a necessary optimality condition for a topology optimization problem for an elastic contact problem with Tresca friction. In the paper a quasistatic contact model is considered, rather than a stationary one used in the literature. The functional approximating the normal contact stress is chosen as the shape functional. The aim of the topology optimization problem considered is to find the optimal material distribution inside a design domain occupied by the...
This paper deals with the formulation of the necessary optimality condition for a topology optimization problem of an elastic body in unilateral contact with a rigid foundation. In the contact problem of Tresca, a given friction is governed by an elliptic variational inequality of the second order. The optimization problem consists in finding such topology of the domain occupied by the body that the normal contact stress along the contact boundary of the body is minimized. The topological derivative...
We define and characterize weak and strong two-scale convergence in Lp,
C0 and other spaces via a transformation of variable, extending Nguetseng's definition.
We derive several properties, including weak and strong two-scale compactness;
in particular we prove two-scale versions of theorems of
Ascoli-Arzelà, Chacon, Riesz, and Vitali.
We then approximate two-scale derivatives, and define two-scale convergence in
spaces of either weakly or strongly differentiable functions.
We also derive...
Currently displaying 141 –
160 of
187