There has been a continuous interest in the analysis of ground-penetrating radar systems and related applications in civil engineering [1]. Consequently, a deeper insight of scattering phenomena occurring in a lossy half-space, as well as the development of sophisticated numerical methods based on Finite Difference Time Domain (FDTD) method, Finite Element Method (FEM), Boundary Element Method ...

An adaptive fast multipole boundary element method (FMBEM) for general three-dimensional (3-D) potential problems is presented in this paper. This adaptive FMBEM uses an adaptive tree structure that can balance the multipole to local translations (M2L) and the direct evaluations of the near-field integrals, and thus can reduce the number of the more costly direct evaluations. Furthermore, the c...

We develop new stabilized mixed finite element methods for Darcy flow. Stability and an a priori error estimate in the ‘‘stability norm’’ are established. A wide variety of convergent finite elements present themselves, unlike the classical Galerkin formulation which requires highly specialized elements. An interesting feature of the formulation is that there are no mesh-dependent parameters. N...

ה ןויעה םוי 35 חשיא לש " מ 0 1 רבוטקואב 013 2 , ןב תטיסרבינוא ןוירוג , ראב עבש , לארשי

Nonnested multigrid methods are shown to be optimal-order solvers for systems of finite element equations arising from elliptic boundary problems in any space dimension. Results are derived for Lagrange-type elements of arbitrary degree.

latticed columns are frequently used in industrial steel structures. in some countries these built-up columns might be even used in other types of steel structures such as residential and commercial buildings. besides, latticed columns are parts of skeletons of many historic buildings all around the world. to analyze a steel structure with latticed columns a more accurate numerical model for su...

The paper examines three selective schemes for the smoothed finite element method (SFEM) which was formulated by incorporating a cell-wise strain smoothing operation into the standard compatible finite element method (FEM). These selective SFEM schemes were formulated based on three selective integration FEM schemes with similar properties found between the number of smoothing cells in the SFEM...

A lattice dynamical finite-element method (LDFEM) is proposed for multiscale analysis of stressed complex crystals. Interatomic potential is embedded into the constitutive relation within the hyperelasticity framework, and two energy-based lattice instability criteria, the K criterion and the soft phonon criterion, are incorporated into LDFEM for capturing stress-driven instabilities in a perfe...

INTRODUCTION The finite element method (FEM) is a numerical technique to obtain an approximate solution of partial differential equations. Mathematical models of many engineering problems can be expressed as partial differential equations that do not have a closed formed solution and therefore require a numerical solution procedure. The FEM approximation requires the discretization of the probl...