| Project/Area Number |
63850100
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
土木構造
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| Research Institution | Saitama University |
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Principal Investigator |
YAMAGUCHI Hiroki Saitama Univ., Fac. of Eng., Assoc. Prof., 工学部, 助教授 (50134474)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Shunichi Nippon Steel Corp., Bridge Eng. Div., 設計部(平成元年2月1日より、新日鉄(株)より出向), 係長
FUJINO Yozo Univ. of Tokyo, Fac. of Eng., Assoc. Prof., 工学部, 助教授 (20111560)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1989: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1988: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | Cable / Modal Damping / Internal Damping / Vibration Control / High-Damping Cable / 球形ダンパ- / ケーブル / モード減衰 / 支点減衰 / 振動実験 / 有限要素法 / 制振 |
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| Research Abstract |
1. The modal damping of flexural oscillation in suspended cable was investigated through free oscillation experiments with cable model and through finite element analyses. The brief conclusions obtained are as follows: (1) Primary causes of modal damping of cable are the internal damping caused by the hysteretic energy loss and the support damping due to the energy loss at support. (2) The internal damping of cable is in proportion to the square of additional dynamic strain of free oscillation. The modal damping of in-plane symmetric mode is, therefore, larger than other modal damping in the modal transition region. (3) The internal damping of cable is larger for lower initial tension but almost independent on the initial tension when the initial tension exceeds about 20 percent of the tensile strength. (4) The flexibility of support has significant effect upon the modal damping of symmetric mode in the region of modal transition. (5) Contribution of support damping to modal damping of suspended cable is approximately proportional to the square of modal support-amplitude.
2. The feasibility study on high-damping cable was conducted with the following ideas; the increase of hysteretic energy loss due to the increase of dynamic strain which may be caused by making the cable non-uniform; the addition of shear damping by inserting viscoelastic materials into cable; and the addition of external damping by using small spherical damper with liquid or lead grains.
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