| タイトル | The Joint Damping Experiment (JDX) |
| 本文（外部サイト） | http://hdl.handle.net/2060/19970021575 |
| 著者（英） | Ferney, Greg D.; Dutson, Joseph D.; Bingham, Jeff G.; Crookston, Jess R.; Rowsell, Edwin A.; Ferney, Brook D.; Folkman, Steven L. |
| 著者所属（英） | Utah State Univ. |
| 発行日 | 1997-06-01 |
| 言語 | eng |
| 内容記述 | The Joint Damping Experiment (JDX), flown on the Shuttle STS-69 Mission, is designed to measure the influence of gravity on the structural damping of a high precision three bay truss. Principal objectives are: (1) Measure vibration damping of a small-scale, pinjointed truss to determine how pin gaps give rise to gravity-dependent damping rates; (2) Evaluate the applicability of ground and low-g aircraft tests for predicting on-orbit behavior; and (3) Evaluate the ability of current nonlinear finite element codes to model the dynamic behavior of the truss. Damping of the truss was inferred from 'Twang' tests that involve plucking the truss structure and recording the decay of the oscillations. Results are summarized as follows. (1) Damping, rates can change by a factor of 3 to 8 through changing the truss orientation; (2) The addition of a few pinned joints to a truss structure can increase the damping by a factor as high as 30; (3) Damping is amplitude dependent; (4) As gravity induced preloads become large (truss long axis perpendicular to gravity vector) the damping is similar to non-pinjointed truss; (5) Impacting in joints drives higher modes in structure; (6) The torsion mode disappears if gravity induced preloads are low. |
| NASA分類 | Spacecraft Design, Testing and Performance |
| レポートNO | 97N22524
NASA-CR-4781
NAS 1.26:4781 |
| 権利 | No Copyright |
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