Dynamic condensation approach for nonclassically damped structures

An iterative dynamic condensation procedure for calculating the eigenproper ties of damped dynamic systems is presented. The kept and reduced degrees o f freedom of the systems are related through dynamic condensation matrices. The formulation to define the condensation matrices is developed. The proc edure starts with a classical static condensation scheme but iteratively im proves the results. The complex eigenproperties calculated in an iteration step are used to construct an updated condensation matrix for the following iteration step, which in turn is utilized to form a revised condensed syst em. A few iterations can provide accurate values of the eigenproperties. Th e iterative process can be expedited initially by a proper selection of the kept and reduced coordinates. Numerical results are presented to demonstra te the accuracy and convergence characteristics of the proposed condensatio n scheme.