Elastomeric damper model for rotorcraft comprehensive analysis

A physics-based elastomeric damper model was integrated in Rotor craft Comprehensive Analysis System (RCAS) to support the analysis and design of rotorcraft and dampers. The model was formulated based on a finite element anelastic displacement fields (ADF) method for elstomeric materials¹ and within the framework of finite element based, nonlinear multibody dynamics that ensure the models for systems of arbitrary topology. A 1-D ADF-based single finite element was used in the model development which is capable of capturing the material nonlinearity with good accuracy and have a high degree of computational efficiency when integrated in a rotorcraft aeromechanical analysis program. Validation studies demonstrated the accuracy of the damper model for typical single and dual frequency operating conditions. Evaluations of the damper model using a typical high fidelity rotor blade model were also performed and demonstrate the convergence of the rotor model as well as the capability of the damper model to capture the material non linearity.