Aeroelastic Analysis of Rotor Blades Using Flexible Multibody Dynamics With Geometrically Nonlinear 3D Finite Elements

This paper presents a flexible multibody dynamics formulation for rotor blade control mechanisms based on three-dimensional (3D) solid finite elements. The formulation accommodates joint rotations within solid elements and is developed using a nonlinear updated Lagrangian (UL) approach. To capture aeroelastic behavior, the structural solver is coupled with a panel/vortex particle hybrid method via the delta airloads approach. The methodology is validated using a simplified hub system and the multi-purpose unmanned helicopter (MPUH) blade developed by the Korea Aerospace Research Institute (KARI). The accuracy of the proposed multibody formulation and aeroelastic analysis in forward flight is assessed through comparison with ABAQUS and CAMRAD II results, demonstrating good agreement in both structural response and aerodynamic performance.