A NEW FAMILY OF MODE-SUPERPOSITION METHODS FOR RESPONSE CALCULATIONS

A new family of mode-superposition methods for the computation of the forced response of proportionally damped systems with and without rigid body modes is investigated. The method may be considered to be an extension of the mode-acceleration method. It allows response calculations to be done with a very small subset of the modes of the system. Numerical examples are given for systems of order 20 and 40. Execution times and number of modes required for convergence are recorded. The particular order of the method among the family which takes the shortest time is determined for the example systems. Time savings with the new method are realized compared to the existing mode-displacement and mode-acceleration methods. The method is expected to be particularly suitable for large systems