ABSTRACT
This chapter shows how one forms the element stiffness matrix, and in the example authors have assembled a global stiffness matrix for a simple truss. It employs the principle of total potential energy for an element to formulate the equation of equilibrium in terms of nodal displacements. The chapter considers that initial strain and residual stress are present, both indicated by the subscript zero. It also considers the nodes of an element as separate entities, leaving the element minus the nodes as a separate entity. The chapter presents in a physically meaningful manner a rather general set of procedures and definitions for finite elements that will serve many of needs.
