In this paper, the finite element analysis of two-dimensional linear viscoelastic problems is performed using quadrilateral complex Fourier elements and, the results are compared with those obtained by quadrilateral classic Lagrange elements. Complex Fourier shape functions contain a shape parameter which is a constant unknown parameter adopted to enhance approximation’s accuracy. Since the iso...

The recently developed consecutive-interpolation procedure (CIP) based 4-node quadrilateral element (CQ4) is used to study free and forced 2-dimensional vibrations of elastic and piezoelectric structures of complex geometries. For some of these problems results have also been computed with the standard quadrilateral element under the constraint that the two approaches have the same number of de...

In this paper, double integrals over an arbitrary quadrilateral are evaluated exploiting finite element method. The physical region is transformed into a standard quadrilateral finite element using the basis functions in local space. Then the standard quadrilateral is subdivided into two triangles, and each triangle is further discretized into 4 n right isosceles triangles, with area 1 2n2, and...

Subelement patterns using bisection of edges and schemes for selecting edges to be split are described for the local refinement of elements in all-quadrilateral and quadrilateral-dominant planar meshes. Subelement patterns using trisection of edges are also described for the local refinement of elements in all-quadrilateral planar meshes. These patterns and schemes are easily extendible to quad...

A multilevel adaptive refinement technique is presented for unstructured quadrilateral meshes in which the mesh is kept conformal at all times. This means that the refined mesh, like the original, is formed of only quadrilateral elements that intersect strictly along edges or at vertices, i.e., vertices of one quadrilateral element do not lie in an edge of another quadrilateral. Elements are re...

In this paper, we introduce a new family of mixed finite element spaces of higher order (k ≥ 1) on general quadrilateral grids. A typical element has two fewer degrees of freedom than the well-known RaviartThomas finite element RT[k], yet enjoys an optimal-order approximation for the velocity in L 2-norm. The order of approximation in the divergence norm is one less than the velocity, as is com...

This paper discusses the modification of Varignon's theorem on quadrilaterals by dividing sides quadrilateral into three, four, five to become parts. The process proving it is done in a very simple way, namely using congruence. result obtained that area ​​the plane formed from has relationship with basic quadrilateral.

In the initial phase of structural part design, wire-frame models are sometimes used to represent the shapes of curved faces. Finite element analysis (FEA) of the curved faces requires that a well-shaped, well-sized mesh be smoothly generated on them. The algorithm described in this paper generates such a mesh from a wireframe model by the following three steps: (1) projection of the vertices o...

A new simple and accurate four-node quadrilateral element is developed for linear static and dynamic analysis of thin to moderately thick laminated, anisotropic plate/shell structures within the first-order shear deformation theory (FSDT). The element is built by incorporating the strain smoothing method of mesh-free conforming nodal integration into the conventional bilinear four-node quadrila...

We study the approximation properties of some finite element subspaces of H(div; Ω) andH(curl ; Ω) defined on hexahedral meshes in three dimensions. This work extends results previously obtained for quadrilateral H(div; Ω) finite elements and for quadrilateral scalar finite element spaces. The finite element spaces we consider are constructed starting from a given finite dimensional space of ve...