Evaluation of an Advanced Finite Element Analysis for Rotor Blades

The performance of an advanced finite element analysis, DYMORE (DYnamic MOdal REissner), being developed by Sikorsky in conjunction with the Rensselaer Polytechnic Institute, has been evaluated. The analysis preprocessor calculates the natural vibrations of a rotor blade and when linked to Sikorsky's primary aeroelastic code yields nonlinear responses of a rotor blade. The capability eliminates restrictions on the sizes of displacements and rotations allowed and its scope is redundant load path rotors with composite material structures. Comparisons are described between linearized modal solutions and nonlinear responses to aerodynamic and specified loadings. Results are also given for a time finite element analysis using physical coordinates. Problems related to solution schemes and the DYMORE approach are discussed. These are significant for the implementation of advanced finite element codes.