Development of the IRS component dynamic reduction method for substructure analysis

The Improved Reduced System (IRS) is a new method for dynamic matrix condensation. It extends the Guyan reduction method by including additional terms which better approximate the mass effects at omitted degrees of freedom. The original implementation of the IRS method was formulated to operate on system modes. This paper describes an extension of the IRS method which accurately processes component modes of substructure models. The resulting capability is extremely useful in creating reduced test-analysis models for modal survey test-analysis correlation.