Journal Published Online: 01 September 1973
Volume 1, Issue 5

An Analog Control System for an Inverted Torsion Pendulum



An analog system has been designed, constructed, and tested for driving an inverted torsion pendulum used in determining damping and internal friction properties of materials. The system is capable of determining log decrements from the electrical characteristics of the system from 10−4 to 10−1 at stresses from 102 to 105 psi with the results being plotted directly by an X–Y recorder. Other variables can be plotted on the x axis in addition to stress, such as magnetic field strength, temperature, time, and axial loads to make this a valuable instrument in the field of metallurgical research. Initial results using this system have shown them to compare almost exactly with those obtained using the usual free decay method.

Author Information

Willertz, LE
Westinghouse Research Laboratories, Pittsburgh, Pa.
Pradhan, AH
Westinghouse Research Laboratories, Pittsburgh, Pa.
Pages: 7
Price: $25.00
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Stock #: JTE10039J
ISSN: 0090-3973
DOI: 10.1520/JTE10039J