Modal Elastic Component Enhancements for RCAS

This paper describes a modal synthesis method for efficiently representing elastic sub-structures within a comprehensive analysis. This capability provides modeling flexibility and can be used to include complex modal sub-structures that would not be easily represented by the elastic beam models available in comprehensive analysis. The modal synthesis method is formulated such that the dynamics of the combined system are preserved, including inertial crosscoupling effects and boundary condition modeling. The application and validity of the modal synthesis approach is demonstrated using the Rotorcraft Comprehensive Analysis System (RCAS). The modal synthesis approach is also evaluated and compared against that of the existing full-vehicle modal approach available in RCAS.