1989 Fiscal Year Final Research Report Summary
Thermoelastic Behavior and Stability of the Spacecraft Booms
| Project/Area Number |
62460074
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Aerospace engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
SUMI Seinosuke Kyushu University, Faculty of Engineering, Professor, 工学部, 教授 (10037947)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Takashi Kyushu University, Faculty of Engineering, Research Associate, 工学部, 助手 (40038071)
HASHIMOTO Yoshio Kyushu University, Research Institute for Applied Mechanics, Assistant Professor, 応用力学研究所, 講師 (80180842)
YAMASAKI Masahide Kyushu University, Faculty of Engineering, Research Associate, 工学部, 助手 (00038085)
MUROZONO Masahiko Kyushu University, Faculty of Engineering, Assistant Professor, 工学部, 講師 (10190943)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Artificial Satellite / Thin-Walled Boom / Structural Dynamics / Thermoelasticity / Thermally Induced Vibration / Stability Analysis / Self-Excited Vibration |
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| Research Abstract |
Theoretical analyses of the thermally induced bending vibration of the thin-walled circular closed section boom are presented for both the cases heated by solar radiation and by a lamp in the laboratory.
And experimental verifications of these results are carried out by both the experiments in air and in vacuum.
First, uniform circular section boom with a tip mass is modeled as a single-degree-of-freedom model. The governing equations are formulated assuming that the boom is heated by the unidirectional solar radiation and that net heat absorption depends on the angle of incidence of heat radiation with respect to the boom. The closed form equation of the boundary of unstable region is obtained by considering the small vibration around the static deflection, and the boundary curves which divide the system parameter plane into regions of stability and instability are also presented. Next, similar analysis is presented using the continuous system model. In this case, the method of solution
… More
consists of applying the Laplace transform with respect to the time to the equation and to the time-dependent boundary conditions, and of obtaining the response by a numerical inversion of the transformed solution. Furthermore, the basic equations for the experiments under the laboratory conditions are also formulated by taking account of the effect of the gravity and assuming that the irradiation of the boom surface changes proportional to its deflection. An occurrence of the thermally induced bending vibration caused by radiant heating is verified by the experiment under laboratory conditions in air. Thin-walled circular section boom made of stainless steel with a tip mass is heated by an infrared lamp which is used as a source of the unidirectional radiation. Responses of the tip displacement of the boom are measured and it is shown that the self-excited bending vibrations can occur actually when the irradiation is large. Frequencies of the thermally induced vibrations, the stability boundaries and the instability characteristics presented by the total damping ratio are well consistent with the theoretically predicted results. Finally, similar experiments are carried out in vacuum making use of the large vacuum chamber. The relations of the phase angle in responses of the perturbation temperature of the boom surface and of the tip deflection of the boom is found, and then it is clarified that the thermally induced bending vibration of the boom is caused by the unsteady thermal bending moment due to the temperature fluctuation having the phase lag near 90ﾟ. Less
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