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Title |
Validation of CF-TMD’s Feedback Control Performance
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Authors |
전승곤(Seung-Gon Jeon) ; 방건혁(Geon-Hyeok Bang) ; 허광희(Gwang-Hee Heo) ; 이재훈(Jae-Hoon Lee) |
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DOI |
https://doi.org/10.11112/jksmi.2026.30.1.62 |
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Keywords |
CF-TMD; 동조이탈; 진동제어; 거동특성; Bang-Bang 알고리즘 CF-TMD; Off-tuning; Control vibration; Response characteristics; Bang-Bang algorithm |
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Abstract |
Large-scale civil engineering structures such as bridges are subjected to various dynamic loads, and when the structural natural frequency coincides with the excitation frequency, resonance may cause a drastic amplification of the structural response. TMD have been widely employed to mitigate such problems; however, their parameters are fixed to the natural frequency assumed at the design stage, so that changes in the structural dynamic characteristics can lead to off-tuning, which may even amplify vibrations. In this study, a CF-TMD(Controlled Friction-Tuned Mass Damper) is developed in which the friction force is switched on and off by electromagnetic force, and a Bang?Bang feedback control algorithm is applied to experimentally verify its vibration mitigation performance. For this purpose, sinusoidal excitation tests are conducted on a cable-stayed bridge model at the first resonant frequency of 3.50 Hz and at 3.65 Hz, where off-tuning occurs, and three cases?uncontrolled, TMD, and CF-TMD?are compared.
The experimental results show that, at 3.50 Hz, the maximum displacement in the uncontrolled case (8.35 mm) is reduced to 1.36 mm (a reduction of approximately 83.7%) with the TMD, and further to 1.24 mm (about 85.1% reduction) with the CF-TMD, demonstrating superior control performance. In addition, at 3.65 Hz, the maximum displacement increases from 2.97 mm to 4.06 mm when the TMD is applied, indicating vibration amplification due to off-tuning, whereas it decreases to 2.24 mm when the CF-TMD is applied, corresponding to a displacement reduction of about 24.6% compared with the uncontrolled case. These results confirm that the CF-TMD can provide stable vibration control not only at the resonant frequency but also in the frequency range where off-tuning occurs.
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