The objective of this study was to perform experiments and analyses of bird strike impact loading on composite panels that represent a section of a composite compressor blade. The bird strike configuration studied was the impact of a gelatin bird simulant material at various impact conditions into composite panels that represent a simplified compressor blade geometry. The tests were designed to have a geometry and boundary conditions (free) that could easily be modeled in the finite element analyses. In addition the test geometry was good for comparing performance of different composite material systems. The experiments were performed using a gas gun and sabot system as described in the reference below. Typical tests used artificial birds of between 1.0 and 2.5 lbs (0.45 and 1.1 kg) and impact velocities between 850 and 1200 ft/second (270 and 360 m/s).

All of the experiments performed used a cylinder of bird simulant material as an impactor. The artificial birds used in this study consist of a mixture of water, gelatin, and phenolic microballoons shaped in the form of a right circular cylinder and have a density of 0.91 g/cm³ (0.033 lb/in³). An advantage of this artificial bird is the uniformity and repeatability of the loading that can be produced from test to test. Thus the results are easily used for validation of numerical simulations.

The analyses of the bird strike tests were performed using the DYNA3D finite element code. An example simulation is shown in Figure 1 or in Movie 1. The response of the artificial bird is similar to a fluid where the strength of the bird simulant material is small compared to the impact loads. The resulting inertial loading excites a variety of flexural modes in the composite panel.

Figure 1 Impact Testing Analysis of a Bird Strike Test on a Composite Panel.

Movie 1 Bird Strike Simulation: Impact on a Composite Panel JPEG Quicktime Video (683 Kb)

T.H. Antoun, P.R. Gefken, B.S. Holmes, and S.W. Kirkpatrick, "Description of a Six-Inch Gas Gun Facility for Soft Body Impact," Proceedings 43rd Annual Meeting of the Aeroballistic Range Association (ARA), Paper No. 50, Sept. 28 to Oct. 2, 1992.

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