Stiffness Matrix for a Simply Supported Beam

This script uses similarities in stiffness coefficients to construct the K matrix for an MDOF system

Input DOF, E, I, L (total beam length), and an optional stiffness multiplier vector (length DOF+1) alpha and return the statically condensed stiffness matrix of a simply supported beam. The beam is divided into DOF+1 equal spans and the full 2*DOF x 2*DOF stiffness matrix is constructed (translation & rotation dofs). This is then statically condensed to a DOF x DOF stiffness matrix (just translation DOF).

The only required input is DOF. If only DOF is provided, E, I, & L will be randomly selected from a specified range.