Symmetry-adapted equilibrium matrices

A number of authors have previously used group representation theory to block-diagonalise the sti€ness matrix of a symmetric structure. This paper describes how similar techniques can be used to block-diagonalise the equilibrium matrix of a symmetric structure. This is shown to provide useful insight into the static and kinematic response of such systems. In particular, it simpli®es ®nding and classifying states of self-stress and mechanisms, as well as reducing the computational e€ort required for a Force Method analysis