Three-Dimensional CAD-Based Structural Modeling for Next Generation Rotor Dynamic Analysis

This paper describes the generation of three-dimensional structural models for systems of multiple flexible bodies. These models are to be analyzed using a next generation, high-fidelity, multibody solver that treats flexible parts with full 3-D finite element analysis. A workflow for creating these models has been developed and is described in detail, starting from geometry created using computer aided design (CAD) tools, proceeding to structural analysis representations, finite element discretization of the flexible components, and definitions of joints and devices to form a final structural analysis model. Three rotor configuration models have been created: a bearingless rotor, an articulated rotor, and a teetering rotor. Initial static and dynamic analyses of these rotors have been performed, verifying the proper integration of the new structural models with the solver. Though this paper focuses on the creation of helicopter rotor models, the method is general and may be applied to many different structural assemblies.