Accession Number : ADA268402


Title :   A Mechanical System Damping Measurement Technique Using a One-Degree-of-Freedom (1DOF) Cylindrical Gas Bearing


Descriptive Note : Final rept. 13 Feb-30 Sep 1992


Corporate Author : ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN


Personal Author(s) : Ratliff, C L ; Marquart, E J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a268402.pdf


Report Date : Aug 1993


Pagination or Media Count : 50


Abstract : An experimental investigation was conducted in the Airflow Calibration Laboratory (ACL) to separate the total rolling moment of rigid and nonrigid mechanical systems into viscous damping and coulomb rolling-moment components. The test technique consisted of measuring roll rate decay of these rigid and nonrigid mechanical systems on a one-degree-of-freedom (1 DOF) cylindrical gas bearing. To better understand the 1 DOF bearing tare damping, a significant amount of information was collected about the operational characteristics of the 1DOF cylindrical gas bearing at certain test conditions. The 1DOF bearing characteristics and test technique are described in this report. The application of the test technique developed for this investigation could be beneficial for determining damping properties of other mechanical systems such as turbomachinery, space structures, gas/ball bearings, and high-damping-capacity materials. The primary measurement uncertainties for the present investigation were determined as follows: +/- 0.01 deg/sec for roll rate obtained with a one-spot tachometer ring, +/- 0.001 in.-lbf for viscous damping moment, or, in terms of energy dissipation, +/- 1 mW. The coulomb rolling-moment uncertainty could not be established because of its variable nature.... Mechanical damping, Viscous damping moment, Coulomb rolling moment, Roll, Gas bearing, Structural damping, Film gap, Tare, Moment of inertia, Energy dissipation, Rigid and nonrigid.


Descriptors :   *BALL BEARINGS , *CYLINDRICAL BODIES , *DAMPING , *DEGREES OF FREEDOM , *GAS BEARINGS , *MEASUREMENT , CALIBRATION , DECAY , DISSIPATION , ENERGY , FILMS , MATERIALS , MECHANICAL PROPERTIES , MOMENT OF INERTIA , RATES , RIGIDITY , RINGS , ROLL , SPACE SYSTEMS , STRUCTURES , TACHOMETERS , TEST AND EVALUATION , TURBOMACHINERY , UNCERTAINTY , VARIABLES , VISCOSITY


Subject Categories : Machinery and Tools
      Fluid Mechanics
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE