Experiments have been made to establish the physical properties of a flexible polyurethane foam plastic used in the construction of aeroelastic models for use in low-speed wind tunnels, Simple static and dynamic bending tests were made on a composite cantilever of plastic foam and a light alloy bar. It is shown that dynamic stiffness and damping capacity measurements must take account of temperature and absolute humidity, and that the dynamic stiffness was approximately double the static value over the very limited frequency range considered. Other phenomena such as creep and the effect of ‘working' are discussed.
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