Abstract
The group-representation theory guarantees that the (tangent) stiffness matrix of symmetric structures can be put into a block-diagonal form by means of a suitable (local) geometric transformation. This transformation decomposes the linear equilibrium equation of symmetric structures into a number of independent equations, and hence is advantageous for parallel analysis. The block-diagonalization method, which so far has mainly been applied for translational displacements, is extended here to rotational ones. The interrelationship between the symmetries of rotational and translational displacements is investigated by means of group theory to arrive at the transformation matrix of rotational ones.
