ABSTRACT
The analysis presented in Section 2.1 resulted in an expression for the stiffness matrix of a bar in its local co-ordinate system. The derivation was based on an immediate appeal to equilibrium to establish the force and, hence, stress distribution in the bar. This method works well for the bar element of constant cross-section, for which exact expressions for the entries in the stiffness matrix are readily deduced. This bar element might be regarded as unusual in that the finite element formulation is exact. In more general cases, the development of the element stiffness matrix might not be so straightforward, and some approximation might be necessary. In these situations there are alternative approaches that might be easier to apply to generate the stiffness terms. An alternative approach to the formulation of the one-dimensional problem will now be presented.
