152 research outputs found
A low-order nonconforming finite element for Reissner-Mindlin plates
We propose a locking-free element for plate bending problems, based
on the use of nonconforming piecewise linear functions for both rotations and
deflections. We prove optimal error estimates with respect to both the meshsize
and the analytical solution regularity
A Virtual Element Method for elastic and inelastic problems on polytope meshes
We present a Virtual Element Method (VEM) for possibly nonlinear elastic and
inelastic problems, mainly focusing on a small deformation regime. The
numerical scheme is based on a low-order approximation of the displacement
field, as well as a suitable treatment of the displacement gradient. The
proposed method allows for general polygonal and polyhedral meshes, it is
efficient in terms of number of applications of the constitutive law, and it
can make use of any standard black-box constitutive law algorithm. Some
theoretical results have been developed for the elastic case. Several numerical
results within the 2D setting are presented, and a brief discussion on the
extension to large deformation problems is included
Virtual Elements for the Navier-Stokes problem on polygonal meshes
A family of Virtual Element Methods for the 2D Navier-Stokes equations is
proposed and analysed. The schemes provide a discrete velocity field which is
point-wise divergence-free. A rigorous error analysis is developed, showing
that the methods are stable and optimally convergent. Several numerical tests
are presented, confirming the theoretical predictions. A comparison with some
mixed finite elements is also performed
A Stress/Displacement Virtual Element Method for Plane Elasticity Problems
The numerical approximation of 2D elasticity problems is considered, in the
framework of the small strain theory and in connection with the mixed
Hellinger-Reissner variational formulation. A low-order Virtual Element Method
(VEM) with a-priori symmetric stresses is proposed. Several numerical tests are
provided, along with a rigorous stability and convergence analysis
A three-dimensional Hellinger-Reissner Virtual Element Method for linear elasticity problems
We present a Virtual Element Method for the 3D linear elasticity problems,
based on Hellinger-Reissner variational principle. In the framework of the
small strain theory, we propose a low-order scheme with a-priori symmetric
stresses and continuous tractions across element interfaces. A convergence and
stability analysis is developed and we confirm the theoretical predictions via
some numerical tests.Comment: submitted to CMAM
SUPG-stabilized Virtual Elements for diffusion-convection problems: a robustness analysis
The objective of this contribution is to develop a convergence analysis for
SUPG-stabilized Virtual Element Methods in diffusion-convection problems that
is robust also in the convection dominated regime. For the original method
introduced in [Benedetto et al, CMAME 2016] we are able to show an "almost
uniform" error bound (in the sense that the unique term that depends in an
unfavorable way on the parameters is damped by a higher order mesh-size
multiplicative factor). We also introduce a novel discretization of the
convection term that allows us to develop error estimates that are fully robust
in the convection dominated cases. We finally present some numerical result
A Stability Study of some Mixed Finite Elements for Large Deformation Elasticity Problems
We consider the finite elasticity problem for incompressible
materials, proposing a simple bidimensional problem for which we provide an
indication on the solution stability. Furthermore, we study the stability of
discrete solutions, obtained by means of some well-known mixed finite elements,
and we present several numerical experiments
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