Resonance Devices with Free Oscillations

Compound Resonance Devices with Free Oscillations 

An example of a free oscillation device whose deformation geometry is torsion of a circular cylinder is shown in Fig. 6-7. The apparatus of Plazek, Vrancken, and Berge mentioned above under creep is equipped here with a moment arm to provide an adjustable moment of inertia. The oscillations are followed by reflection of a light beam from a mirror attached to the rotating unit onto a photocell, whose output is automatically recorded. From the trace (Fig. 6-8), the characteristic frequency cOc and the decrement A can be obtained it is convenient to match with an adjustable enlarger to standard exponential envelopes. The decrement is proportional to the slope of a plot of the logarithm of the maximum amplitude 

Torsion pendulum for dynamic measurements on soft solids with free oscillations (Plazek, Vrancken, and Berge ), with modiHed moment arms. 

The free oscillation devices cover in general a frequency range of 0.01 to 25 Hz. The precise temperature control needed for all viscoelastic measurements can be achieved by suitable design any mechanical connections with parts of the apparatus outside the thermostat must be made through members of low heat conductivity. 

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Compound Resonance Devices with Free Oscillations... 

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