A Torsion Pendulum for Measurement of Damping Capacity and Related Phenomena

Investigation of the damping mechanisms of metals and alloys requires that damping capacity measurements be made over wide stress, frequency, and temperature ranges. The torsion pendulum described herein fulfills these requirements in all respects except that it has a limited (low) frequency range. This versatile apparatus also allows creep, fatigue, stress relaxation, elastic after-effect, static and dynamic moduli and hysteresis curves to be made at temperature and in vacuo. It is possible to superimpose a magnetic field on the specimen during these measurements. The specimen may also be heat treated or plastically deformed in situ. An electronic data processing system has been designed to calculate and plot material damping characteristics during a free decay test. The damping characteristics are thus obtained more quickly and with greater accuracy than was previously possible.