Element Stiffness Matrix Generator

Abstract
This paper presents the basic concepts required to construct a computer code capable of deriving element stiffness matrices. The computer program requires only the displacement functions, transformation matrices, and a few control cards as input. The computer code assembles a complete element stiffness matrix for any type of configuration and displacement functions of any order. The matrix is stored in an alpha-numeric array. The final form is printed in terms of numerical coefficients and material and geometric properties of the element in symbol form. The output is received printed or punched on cards ready for incorporation into existing finite element computer codes. Examples are presented for a two-dimensional triangular plate element in which the displacements are represented in terms of area coordinates. However, the concept is not limited to local coordinate representations of displacement functions or to two-dimensional problems.