This paper presents an explicit integration scheme to compute the stiffness matrix of an eight node linear
convex quadrilateral element for plane problems using symbolic mathematics and an automatic generation
of all quadrilateral mesh technique , In finite element analysis, the boundary problems governed by second
order linear partial differential equations,the element stiffness matrices are expressed as integrals of the
product of global derivatives over the linear convex quadrilateral region. Thes e matrices can be shown to
depend on the material properties and the matrix of integrals with integrands as rational funct ions with
polynomial numerator and the linear denominator (4+ ) in bivariates over an eight node 2- square
(- 1 ).In this paper,we have computed these integrals in exact and digital forms using the
symbolic mathematics capabilities of MATLAB. The proposed explicit finite element integration scheme is
illustrated by computing the Prandtl stress function values and the torisonal constant for the square cross
section by using the eight node linear convex quadrilateral finite elements.An automatic all quadrilateral
mesh generation techniques for the eight node linear convex quadrilaterals is also developed for this
purpose.We have presented a complete program which automatically discritises the arbitrary triangular
H.T.Rathod IJECS Volume 3 Issue 5 May, 2014 Page No.5657-5713 Page 5658
domain into all eight node linear convex quadrilaterals and applies the so generated nodal coordinate and
element connection data to the above mentioned torsion problem.
Key words: Explicit Integration, Gauss Legendre Quadrature, Quadrilateral Element, Prandtl’s Stress
Function for torsion, Symbolic mathematics,all quadrilateral mesh generation technique. Explicit
Integration, eight node element, Gauss Lege ndre Quadrature, Linear Convex Quadrilateral, Stress Function,
Poisson Equation, Torsion Constant.