AN EXPERIMENTAL-TECHNIQUE FOR DETERMINING A MEASURE OF STRUCTURAL DAMPING

An experimental procedure for the determination of structural damping in a material specimen at low frequencies ( less than 20 Hz) and low strain amplitudes ( less than 10** minus **5) is presented. The experimental apparatus entails a beam specimen supported under free-free boundary conditions and vibrated in first-mode flexural resonance. All experiments were carried out in vacuum at frequencies near 20 Hz, and data were automatically acquired using a system of electronic equipment. A measure of structural damping was obtained by reducing the acquired data using a linearized logarithmic decrement technique. Experimental results discussed concern the structural damping of the following specimens: 6061-T6 aluminum, 6061 (annealed) aluminum, and 0 and 90 deg orientation continuous fiber P55Gr/6061Al (graphite/aluminum) metal matrix composite.

AN EXPERIMENTAL-TECHNIQUE FOR DETERMINING A MEASURE OF STRUCTURAL DAMPING Academic Article