DAMPED DYNAMIC SUBSTRUCTURES.

The dynamic substructure method is extended to lightly or heavily damped systems. Both internal and external dampings are considered. The damped dynamic flexibility associated with the slave co-ordinates is first expanded in terms of the damped fixed interface natural modes and the condensed dynamic stiffness associated with the master co-ordinates is formed subsequently. The convergence of the condensed dynamic stiffness with respect to the damped natural modes can be improved by means of the static matrices. Since the dynamic stiffness method is equivalent to the modal synthesis method, the component mode method and Kron's method, the theory presented here is readily applicable to these methods and are restricted to symmetric damping matrices.