• Title/Summary/Keyword: isolation device

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Application of Seismic Base Isolation With Anti-Uplift Device for Arch Structure (아치 구조물의 지진응답 제어를 위한 들림방지 면진장치의 적용)

  • Kim, Gee-Cheol;Lee, Joon-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.4
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    • pp.169-176
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    • 2020
  • When an unexpected excessive seismic load is applied to the base isolation of arch structure, the seismic displacement of the base isolation may be very large beyond the limit displacement of base isolation. These excessive displacement of the base isolation causes a large displacement in the upper structure and large displacement of upper structure causes structural damage. Therefore, in order to limit the seismic displacement response of the base isolation, it is necessary to install an additional device such as an anti-uplift device to the base isolation. In this study, the installation direction of the base isolation and the control performance of the base isolation installed anti-uplift device were investigated. The installation direction of the base isolation of the arch structure is determined by considering the horizontal and vertical reaction forces of the arch structure. In addition, the separation distance of the anti-uplift device is determined in consideration of the design displacement of the base isolation and the displacement of the arch structure.

Effect of the limiting-device type on the dynamic responses of sliding isolation in a CRLSS

  • Cheng, Xuansheng;Jing, Wei;Li, Xinlei;Lu, Changde
    • Earthquakes and Structures
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    • v.15 no.2
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    • pp.133-144
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    • 2018
  • To study the effectiveness of sliding isolation in a CRLSS (concrete rectangular liquid-storage structure) and develop a reasonable limiting-device method, dynamic responses of non-isolation, sliding isolation with spring limiting-devices and sliding isolation with steel bar limiting-devices are comparatively studied by shaking table test. The seismic response reduction advantage of sliding isolation for concrete liquid-storage structures is discussed, and the effect of the limiting-device type on system dynamic responses is analyzed. The results show that the dynamic responses of sliding isolation CRLSS with steel bar-limiting devices are significantly smaller than that of sliding isolation CRLSS with spring-limiting devices. The structure acceleration and liquid sloshing wave height are greatly influenced by spring-limiting devices. The acceleration of the structure in this case is close to or greater than that of a non-isolated structure. Liquid sloshing shows stronger nonlinear characteristics. On the other hand, sliding isolation with steel bar-limiting devices has a good control effect on the structural dynamic response and the liquid sloshing height simultaneously. Thus, a limiting device is an important factor affecting the seismic response reduction effect of sliding isolation. To take full advantage of sliding isolation in a concrete liquid-storage structure, a reasonable design of the limiting device is particularly important.

Behavior Analysis of Base Isolation With Anti-Uplift Device for Arch Structure by Numerical Analysis (아치구조물 적용 인장저항 면진장치의 수치해석적 거동 분석)

  • Kim, Gee-Cheol;Jang, Myung Ho
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.3
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    • pp.99-106
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    • 2020
  • If an excessive displacement occurs in the base isolation system, the structure will be damaged due to overturning of the upper structure. In this study, we analyze the behavior of base isolation by applying earthquake to base isolation with anti-uplift device. In the case of structures that generate horizontal reaction forces such as arch structures, horizontal reaction forces must be considered in the design of the base isolation and structural members. And anti-uplift device for preventing the excessive displacement of the base isolation system is needed.

Study on seismic response of a seismic isolation liquid storage tank

  • Xiang Li;Jiangang Sun;Lei Xu;Shujin Zhang;Lifu Cui;Qinggao Zhang;Lijie Zhu
    • Earthquakes and Structures
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    • v.26 no.5
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    • pp.337-348
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    • 2024
  • This paper presents a new seismic isolation design for liquid storage tank (LST). The seismic isolation system includes: LST, flexible membrane, sand mat and rolling seismic isolation devices. Based on the mechanical equilibrium theory, the symmetric concave rolling restoring force model of the isolation device is derived. Based on the elasticity theory and restoring force model of the seismic isolation, a simplified mechanical model of LST with the new seismic isolation is established. The rationality of the seismic isolation design of LST is explored. Meanwhile, the seismic response of the new seismic isolation LST is investigated by numerical simulation. The results show that the new seismic isolation tank can effectively reduce the seismic response, especially the control of base shear and overturning moment, which greatly reduces the risk of seismic damage. The seismic reduction rate of the new seismic isolation storage tanks in Class I, II, and III sites is better than that in Class IV sites. Moreover, the seismic isolation device can effectively control the ground vibration response of storage tanks with different liquid heights. The new seismic isolation LST design provides better isolation for slender LSTs than for broad LSTs.

Fault Isolation for Linux Device Drivers

  • Son, Sunghoon
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.4
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    • pp.1-8
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    • 2017
  • In this paper, we propose a fault isolation system for device drivers of the Linux operating system. High availability systems impose stringent requirements upon Linux operating system. Especially device drivers can be a major source of operating system instability and many times contribute to system degradation and outages. The proposed fault isolation system identifies the occurrence of the memory-related faults in device driver and isolates it from the kernel. By operating at the early stage of the page fault handler in Linux kernel, the system detects which module causes fault and isolates it transparently from the remaining part of the kernel. By experiments, we show that the proposed system efficiently detects faults incurred by device driver, isolates the device driver and the process which accessed the driver module from the kernel.

Analysis of Seismic Response According to Installation Location of Seismic Isolation System Applied to High-Rise Building (고층 건물에 적용한 면진 시스템의 설치 위치에 따른 지진 응답 분석)

  • Kim, Min-Ju;Kim, Dong-Uk;Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.4
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    • pp.81-88
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    • 2018
  • Seismic isolation systems have typically been used in the form of base seams in mid-rise and low-rise buildings. In the case of high-rise buildings, it is difficult to apply the base isolation. In this study, the seismic response was analyzed by changing the installation position of the seismic isolation device in 3D high - rise model. To do this, we used 30-story and 40-story 3D buildings as example structures. Historic earthquakes such as Mexico (1985), Northridge (1994) and Rome Frieta (1989) were applied as earthquake loads. The installation position of the isolation device was changed from floor to floor to floor. The maximum deformation of the seismic isolation system was analyzed and the maximum interlaminar strain and maximum absolute acceleration were analyzed by comparing the LB model with seismic isolation device and the Fixed model, which is the base model without seismic isolation device. If an isolation device is installed on the lower layer, it is most effective in response reduction, but since the structure may become unstable, it is effective to apply it to an effective high-level part. Therefore, engineers must consider both structural efficiency and safety when designing a mid-level isolation system for high-rise buildings.

Parametric Study of Asymmetric Base-Isolation Coupling Control System for Vibration Control of Adjacent Twin Buildings (쌍둥이 인접구조물의 진동 제어를 위한 비대칭 지진격리 연결 제어시스템의 매개변수연구)

  • Kim, David;Park, Wonsuk;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.37 no.3
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    • pp.45-51
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    • 2022
  • This paper focuses on a recently proposed asymmetric base-isolation coupling control system (ABiCS) for the vibration control of adjacent twin buildings. The ABiCS consists of inter-story diagonal dampers, a connecting damper between the two buildings, and a seismic isolation device at the base floor of one building. To investigate the control characteristics of ABiCS, a parametric study was performed by numerically simulating the 20-story twin buildings. In the parametric study, the control capacities of the inter-story diagonal dampers, connecting damper, and seismic isolation device were considered as varying parameters. The parametric study results indicate that the connecting damper between the two buildings reduces the responses of both buildings only at optimal or near-optimal capacity. In addition, adjusting the stiffness of the base isolation is found to be the most effective method for improving seismic performance and achieving cost-effectiveness. Accordingly, we presented a scenario-based performance improvement approach in which reducing the stiffness of the base isolation device could be an effective technique to improve the seismic performance of both buildings. However, note that checking the maximum allowable displacement of the base isolation device is essential.

Dynamic Analysis and Experiments of High Impulsive Force Device with Isolation System (완충시스템을 장착한 고충격 발생기구의 동특성 해석 및 실험)

  • Park, Moon-Sun;Kang, Tae-Ho;Byun, Young-Seop;Song, Joon-Beom;Ku, Tae-Wan;Kang, Beom-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.10
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    • pp.107-114
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    • 2008
  • The aim of this study is to obtain the useful design guideline for high impulsive force device with an isolation system by the analytic approach of dynamics characteristics. In this study, the high impulsive force system was modeled and analyzed in view of multi-body dynamics, and verified the modeling and analysis result by the experiment of the high impulsive force device. Additionally, the dynamic analysis was performed for the isolation system with the selected coefficients of elastic spring and damper selected. Experimental result for the high impulsive force device with the isolation system was compared and analyzed. From the result, it was confirmed that the design guideline for the isolation system of the high impulsive force device was useful.

Analysis of Isolation System in Distinct Multi-mechanism HIF Device (이종 복합 메카니즘 HIF 기구의 충격저감시스템 해석)

  • Choe Eui Jung;Kim Hyo-Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.2
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    • pp.53-59
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    • 2005
  • In this study, the isolation system for multi-mechanism HIF (high impulsive force) device has been investigated. For this purpose, parameter optimization process has been performed based on the simplified isolation system model under constraints of moving displacement and transmitted force. The design parameters for multi-mechanism HIF device have been derived with respect to HIF system I and HIF system II, respectively. In order to implement the dynamic absorbing system, the dual stage hydro-pneumatic damper and magnetorheological damper with semi-active control scheme are considered. Finally, the performance of the designed prototype isolation system has been evaluated by experimental works under actual operating conditions.

An Analysis of Seismic Response of High - Rise Building with Mid-Story Isolation System According to Change of Characteristics of the Seismic Isolation Device (중간층 면진시스템이 적용된 고층건물의 면진장치 특성변화에 따른 지진응답분석)

  • Kang, Joo-Won
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.8
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    • pp.149-156
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    • 2019
  • In this study, dynamic responses of high - rise buildings were analyzed through the change of horizontal stiffness and yield strength among characteristics of seismic isolation system by applying middle - layer seismic isolation system to high - rise buildings of 120m height. As a result in order to prevent the displacement of the isolation layer and to control the maximum torsion angle, it is possible to appropriately control by increasing or decreasing the horizontal stiffness and the yield strength. However, depending on the maximum torsional angle and the hysteretic behavior of the seismic isolation system, excessive yield strength and horizontal stiffness increase may induce the elastic behavior of the structure and amplify the response. Therefore, it is considered that it is necessary to select the property value of the appropriate isolation device.