The number of different eigenmodes in a structure equals the number of degrees of freedom. In case of beams there are six degrees of freedom per node, with only trusses attached, a node possesses three degrees of freedom. Fig. 18.104.22.168 shows the first nine eigenmodes of a triangular beam mesh that is fixed at its lower corners. In the upper left corner of fig. 22.214.171.124 one sees the undeformed shape. The higher the index of an eigenmode the more folds it exhibits.