A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Mitigation Effect of Vortex-Induced Vibration of Suspension Bridge Hangers with Stockbridge dampers ; 스톡브리지 댐퍼의 현수교 행어 와류진동 제진 효과
학위논문 (석사)-- 서울대학교 대학원 : 건설환경공학부, 2016. 2. 김호경. ; PWS is polyethylene-coated hanger cable that has the advantages of maintenance and durability but because of its smooth surface, it has the weakness of wind resistant performance. This paper tries to supplement wind resistant performance by using Stockbridge damper known for mitigating effect of vibration for a cable. For the design of the Stockbridge damper, a suspension bridge in Korea was selected and one of the hanger cables for the bridge was set up for the target hanger cable. Through wind data obtained from anemometer on the bridge, the target frequency range was determined as 5~20Hz. In order to evaluate the vibration of a hanger cable, Stockbridge damper was modeled as 2-DOF system. For verification of 2-DOF model of Stockbridge damper, excitation experiment of Stockbridge damper was carried out with SB8, SB12 and SB16. Dynamic properties obtained from 2-DOF model were compared with dynamic properties extracted from the experiment and the similar results were obtained. Amplitude of vortex-induced vibration was evaluated by Energy Balance Method with dynamic properties obtained from 2-DOF model and results showed that Stockbridge damper mitigates effectively the amplitude of the hanger cable in the vicinity of its natural frequencies. Based on this, asymmetric Stockbridge damper for the target hanger cable was designed and when designed Stockbridge damper was installed to the target hanger cable, the amplitude of the cable satisfied the allowable amplitude on target frequency range. ; CHAPTER 1. INTRODUCTION 1 CHAPTER 2. TARGET HANGER CABLE 3 2.1 DESCRIPTION OF EXAMINED SUSPENSION BRIDGE AND A TARGET HANGER CABLE. 3 2.2 TARGET FREQUENCY RANGE AND ALLOWABLE AMPLITUDE 4 CHAPTER 3. EVALUATION OF MITIGATION EFFECT OF STOCKBRIDGE DAMPER 7 3.1 ENERGY BALANCE METHOD 7 3.1.1 Energy brought by wind 7 3.1.2 Energy dissipated by cable 8 3.1.3 Energy dissipated by Stockbridge damper 8 3.2 DYNAMIC PROPERTIES OF STOCKBRIDGE DAMPER 10 3.2.1 2-DOF model of Stockbridge damper 10 3.2.2 Excitation experiment of Stockbridge damper 12 3.2.3 Comparison of dynamic properties 14 3.3 EVALUATION OF AMPLITUDE FOR A TARGET HANGER CABLE 16 CHAPTER 4. DESIGN OF STOCKBRIDGE DAMPER FOR THE HANGER CABLE 19 4.1 DESIGN PROCESS 19 4.2 DSIGNED STOCKBRIDGE DAMPER 20 CHAPTER 5. CONCLUSION 23 REFERENCES 25 ; Master
Mitigation Effect of Vortex-Induced Vibration of Suspension Bridge Hangers with Stockbridge dampers ; 스톡브리지 댐퍼의 현수교 행어 와류진동 제진 효과
학위논문 (석사)-- 서울대학교 대학원 : 건설환경공학부, 2016. 2. 김호경. ; PWS is polyethylene-coated hanger cable that has the advantages of maintenance and durability but because of its smooth surface, it has the weakness of wind resistant performance. This paper tries to supplement wind resistant performance by using Stockbridge damper known for mitigating effect of vibration for a cable. For the design of the Stockbridge damper, a suspension bridge in Korea was selected and one of the hanger cables for the bridge was set up for the target hanger cable. Through wind data obtained from anemometer on the bridge, the target frequency range was determined as 5~20Hz. In order to evaluate the vibration of a hanger cable, Stockbridge damper was modeled as 2-DOF system. For verification of 2-DOF model of Stockbridge damper, excitation experiment of Stockbridge damper was carried out with SB8, SB12 and SB16. Dynamic properties obtained from 2-DOF model were compared with dynamic properties extracted from the experiment and the similar results were obtained. Amplitude of vortex-induced vibration was evaluated by Energy Balance Method with dynamic properties obtained from 2-DOF model and results showed that Stockbridge damper mitigates effectively the amplitude of the hanger cable in the vicinity of its natural frequencies. Based on this, asymmetric Stockbridge damper for the target hanger cable was designed and when designed Stockbridge damper was installed to the target hanger cable, the amplitude of the cable satisfied the allowable amplitude on target frequency range. ; CHAPTER 1. INTRODUCTION 1 CHAPTER 2. TARGET HANGER CABLE 3 2.1 DESCRIPTION OF EXAMINED SUSPENSION BRIDGE AND A TARGET HANGER CABLE. 3 2.2 TARGET FREQUENCY RANGE AND ALLOWABLE AMPLITUDE 4 CHAPTER 3. EVALUATION OF MITIGATION EFFECT OF STOCKBRIDGE DAMPER 7 3.1 ENERGY BALANCE METHOD 7 3.1.1 Energy brought by wind 7 3.1.2 Energy dissipated by cable 8 3.1.3 Energy dissipated by Stockbridge damper 8 3.2 DYNAMIC PROPERTIES OF STOCKBRIDGE DAMPER 10 3.2.1 2-DOF model of Stockbridge damper 10 3.2.2 Excitation experiment of Stockbridge damper 12 3.2.3 Comparison of dynamic properties 14 3.3 EVALUATION OF AMPLITUDE FOR A TARGET HANGER CABLE 16 CHAPTER 4. DESIGN OF STOCKBRIDGE DAMPER FOR THE HANGER CABLE 19 4.1 DESIGN PROCESS 19 4.2 DSIGNED STOCKBRIDGE DAMPER 20 CHAPTER 5. CONCLUSION 23 REFERENCES 25 ; Master
Mitigation Effect of Vortex-Induced Vibration of Suspension Bridge Hangers with Stockbridge dampers ; 스톡브리지 댐퍼의 현수교 행어 와류진동 제진 효과
방민규 (author) / 김호경 / 공과대학 건설환경공학부
2016-01-01
Theses
Electronic Resource
English
Unsteady Theoretical Analysis on the Wake-Induced Vibration of Suspension Bridge Hangers
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Vortex excitation of bridge hangers
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