Vibration Mitigation of Offshore Platform Utilizing a Magnetorheological Elastomer Damper
- Dingxin Leng (Ocean University of China) | Kai Xu (Ocean University of China) | Guijie Liu (Ocean University of China) | Yingchun Xie (Ocean University of China) | Xiaojie Tian (Ocean University of China)
- Document ID
- International Society of Offshore and Polar Engineers
- The 28th International Ocean and Polar Engineering Conference, 10-15 June, Sapporo, Japan
- Publication Date
- Document Type
- Conference Paper
- 2018. International Society of Offshore and Polar Engineers
- vibration control, magnetorheological elastomer, Offshore platform
- 0 in the last 30 days
- 27 since 2007
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The present paper focus on the effectiveness performance of a MRE damper for vibration control of offshore platform under seismic loadings. MRE materials are fabricated, and a MRE damper in mixing coupling mode is designed. Testing and dynamic modeling of the proposed MRE damper is conducted. Finite element mode of offshore platform with MRE damper is established. The results demonstrated that, by applying proposed MRE damper, the dynamic responses (displacement, acceleration and local stress) of offshore platform under seismic loadings are greatly reduced, which presents MRE damper is an effective semi-active vibration control devices for offshore platform.
For exploration and production of oil and gas, the offshore structure industry has been flourishing since early 1940s (Mao, Zhong, Zhang and Chu,2015). One of the most typical offshore platforms are fixed steel jacket platforms located in water depth from a few meters to more than 300 meters (Ou, Long, Li and Xiao,2007). Offshore platforms should suffer in ocean environment, such as the dynamic loadings including ocean wind, wave, current, earthquake and ice (in high latitude region) (Raheem,2016). Among these ocean environmental loadings, in active fault zone, seismic loading is one of the greatest factors to the fatigue damage of offshore platforms and has a significant role on the operation safety of the offshore platforms (Wu, Shi, Wang, Guan, Ou,2010; Park, Koo, Kawano,2011). To ensure safety, serviceability and make people comfortable on the platform, it should be indispensable to reduce the overall responses (e.g. displacement, velocity and acceleration) of offshore platforms subjected to the seismic loadings.
In last decades, a series of studies have been conducted on vibration control of jacket offshore platforms under earthquake loadings. Jin, Li, Sun, Zhou, Guan (2007) conducted an experimental and numerical study on tuned liquid dampers for controlling earthquake responses of offshore platform; it was found that the ratio of the fundamental sloshing frequency of liquid to the natural frequency of platform was the key factor to control earthquake responses. However, the problem of tuned liquid dampers for vibration control of offshore platform is that the damping ratio is limited. That is, tuned liquid dampers may be very suitable for structures with low damping; however, for offshore platform, the damping ratio reach as high as 4%-5%, the practical control effectiveness of tuned liquid dampers could be much lower than that in the research work. Wu, Shi, Wang, Guan, Ou (2010) utilized rubber bearings and MR damper to reduce the vibration of offshore platform caused by earthquake; Kalman filter was used to estimate the system state and the dynamic responses of structures. The results showed that earthquake-induced vibrations can be effectively by the passive and semi-active damping systems. Wu, Zhao, Zheng, Wa (2016) studied high response performance of a tuned-mass damper for vibration suppression of offshore platform under earthquake loads; and the tuned-mass damper control scheme was compared with tuned-liquid damper and active mass damper control scheme.
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