Experimental Identification of the Structural Properties of an AB 204 Helicopter Blade and F.E. Model Validation

A study was conducted to demonstrate experimental identification of the structural properties of an AB 204 helicopter blade and perform finite element model validation. The developed procedure was based on the sensitivity of frequency response-based correlation functions to changes in the design parameters adopted for the developed updating process. A refinement of the stiff properties of the helicopter blade was accomplished by evaluating the most sensitive parameters that reduced the distance between the experimental dynamic behavior and the analytical behavior. The stiffness distribution of the beam model of the helicopter rotor blade was estimated from the measurements of its vertical displacements with the structure clamped at the root section with a static load and applied at the blade tip. The strain measurement needed to identify the bending stiffness properties was also used to validate the numerical model.