We present a novel approach to fast on-the-fly low order finite element assembly for scalar elliptic partial differential equations of Darcy type with variable coefficients optimized for matrix-free implementations. Our approach introduces a new operator that is obtained by appropriately scaling the reference stiffness matrix from the constant coefficient case. Assuming sufficient regularity, a...

A new iterative approach to steady seepage of ground water with a free surface has been developed using the finite element method. This approach eliminates a number of difficulties that were inherent in the iterative procedures previously used to solve this problem and rapid convergence is now assured in all cases. The method is applicable to heterogeneous porous media with complex geometric bo...

In this paper, a new three dimensional brick finite element based on the strain approach is presented with the purpose of identifying the most effective to analyze linear thick and thin plate bending problems. The developed element which has the three essential external degrees of freedom (U, V and W) at each of the eight corner nodes, is used with a modified elasticity matrix in order to satis...

We propose a new family of finite element methods for the Naghdi shell model, one method associated with each nonnegative integer k. The methods are based on a nonstandard mixed formulation, and the kth method employs triangular Lagrange finite elements of degree k+2 augmented by bubble functions of degree k+ 3 for both the displacement and rotation variables, and discontinuous piecewise polyno...

On arbitrary regular quadrilaterals, a new finite element method for the Reissner-Mindlin plate is proposed, where both transverse displacement and rotation are approximated by isoparametric bilinear elements, with local bubbles enriching rotation, and a local reduction operator is applied to the shear energy term. This new method gives optimal error bounds, uniform in the thickness of the plat...

We propose a new formulation along with a family of finite element schemes for the approximation of the interaction between fluid motion and linear mechanical response of a porous medium, known as Biot’s consolidation problem. The steady-state version of the system is recast in terms of displacement, pressure, and volumetric stress, and both continuous and discrete formulations are analyzed as ...

Abstract:   The theory of optimization has improved remarkably during the last four decades. The main part of optimizing investigations has been focused on enhancing buckling resistance which does not violate the economic feasibility of final design. The finite element analysis which is called ESO (Evolutionary Structural Optimization) is presented for optimum (or most ideal) design of c...

CCHE3D model is developed at the National Center for Computational Hydroscience and Engineering, The University of Mississippi, for simulating unsteady, free surface, three-dimensional turbulent flows and sediment/pollutant transport and water quality. This model is based on Efficient Element Method, a collocation version of the Galerkin approach. The basic element is a cube with twenty-seven n...