Direct Method
The direct method uses such basic principles such as equilibrium, compatibility and material law to formulate the element stiffness matrix, as opposed to more mathematically based approaches, such as the principle of minimum potential energy or weighted residual methods . We will use the direct method to formulate our element stiffness matrix, because it is more intuitive than many concepts that will be used in the more general mathematical formulation approaches of the finite element equations. In addition, one only has to have a background in a sophomore level mechanics of materials (strength of materials) course in order to understand the direct method of element formulation.