Design of a Periodic Structure for Composite Helicopter Rotor Blade

This study investigates the design and optimization of a 3D periodic structure to minimize vibrations in helicopter rotor blade systems.The research focuses on nonlinear models for rotating beams using a hybrid formulation of finite element methods and variational asymptotic beam sectional analysis.The periodic structure attenuates vibration transmitted from the blades to the rotor shaft.Dimension optimization was performed using particle swarm and gradient search algorithms, showing a minimal average difference of 2.37 %.Performance simulations at 190 rpm revealed that a 5.4 % reduction in reaction forces in the X and Y directions and a 3.2 % reduction in Z direction forces of main rotor shaft occur in comparison with conventional damper system.As a result of the study, it was concluded that 3D periodic structures can form a suitable passive damping system and mass reduction solution for helicopter blades.