University of Florida/Eml4500/f08.qwiki/Lecture 6

The global force relationship is given by the equation $F=KD$, where $F$ is the resultant force matrix, $K$ is the global stiffness matrix, and $D$ is the global displacement matrix.

In matrix format,

$k^{e}=k^{e}{\begin{bmatrix}(l^{e})^{2}&(l^{e}m^{e})&-(l^{e})^{2}&-(l^{e}m^{e})\\(l^{e}m^{e})&(m^{e})^{2}&-(l^{e}m^{e})&-(m^{e})^{2}\\-(l^{e})^{2}&-(l^{e}m^{e})&(l^{e})^{2}&(l^{e}m^{e})\\-(l^{e}m^{e})&-(m^{e})^{2}&(l^{e}m^{e})&(m^{e})^{2}\end{bmatrix}}$