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1.
This paper presents an experimental study to explore the possibility of using a hybrid platform to ensure the functionality of high‐tech equipment against microvibration and to protect high‐tech equipment from damage when an earthquake occurs. A three‐storey building model and a hybrid platform model were designed and manufactured. The two‐layer hybrid platform, on which the high‐tech equipment is placed, was installed on the first floor of the building to work as a passive platform aiming at abating acceleration response of the equipment during an earthquake and functioning as an actively controlled platform that intends to reduce velocity response of the equipment under a normal working condition. For the hybrid platform working as a passive platform, it was designed in such a way that its stiffness and damping ratio could be changed, whereas for the hybrid platform functioning as an active platform, a piezoelectric actuator with a sub‐optimal velocity feedback control algorithm was used. A series of shaking table tests, traffic‐induced vibration tests and impact tests were performed on the building with and without the platform to examine the performance of the hybrid platform. The experimental results demonstrate that the hybrid platform is feasible and effective for high‐tech equipment protection against earthquake and microvibration. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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High‐tech equipments engaged in the production of ultra‐precision products have very stringent vibration criteria for their functionality in normal operation conditions and their safety during an earthquake. Most previous investigations were based on simplified planar models of building structures, despite the fact that real ground motions and structures are always three‐dimensional. This paper hence presents a three‐dimensional analytical study of a hybrid platform on which high‐tech equipments are mounted for their vibration mitigation. The design methodology of the hybrid platform proposed in this study is based on dual‐level performance objectives for high‐tech equipments: safety against seismic hazard and functionality against traffic‐induced microvibration. The passive devices (represented by springs and viscous dampers) and the active actuators are designed, respectively, to meet vibration criteria corresponding to safety level and functionality level. A prototype three‐story building with high‐tech equipments installed on the second floor is selected in the case study to evaluate the effectiveness of the hybrid platform. The optimal location of the platform on the second building floor is determined during the design procedure in terms of the minimal H 2 cost function of absolute velocity response. The simulation of the coupled actuator‐platform‐building system subjected to three‐dimensional ground motions indicates that the optimally designed hybrid platform can well achieve the dual target performance and effectively mitigate vibration at both ground motion levels. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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The experimental results of using a hybrid platform to mitigate vibration of a batch of high‐tech equipment installed in a building subject to nearby traffic‐induced ground motion have been presented and discussed in the companion paper. Based on the identified dynamic properties of both the building and the platform, this paper first establishes an analytical model for hybrid control of the building‐platform system subject to ground motion in terms of the absolute co‐ordinate to facilitate the absolute velocity feedback control strategy used in the experiment. The traffic‐induced ground motion used in the experiment is then employed as input to the analytical model to compute the dynamic response of the building‐platform system. The computed results are compared with the measured results, and the comparison is found to be satisfactory. Based on the verified analytical model, coupling effects between the building and platform are then investigated. A parametric study is finally conducted to further assess the performance of both passive and hybrid platforms at microvibration level. The analytical study shows that the dynamic interaction between the building and platform should be taken into consideration. The hybrid control is effective in reducing both velocity response and drift of the platform/high‐tech equipment at microvibration level with reasonable control force. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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This paper presents an experimental study, while a companion paper addresses an analytical study, to explore the possibility of using a hybrid platform to mitigate vibration of a batch of high‐tech equipment installed in a building subject to nearby traffic‐induced ground motion. A three‐storey building model and a hybrid platform model are designed and manufactured. The hybrid platform is mounted on the building floor through passive mounts composed of leaf springs and oil dampers and controlled actively by an electromagnetic actuator with velocity feedback control strategy. The passive mounts are designed in such a way that the stiffness and damping ratio of the platform can be changed. A series of shaking table tests are then performed on the building model without the platform, with the passive platform of different parameters, and with the hybrid platform. The experimental results demonstrate that the hybrid platform is very effective in reducing the velocity response of a batch of high‐tech equipment in the building subject to nearby traffic‐induced ground motion if dynamic properties of the platform and control feedback gain are selected appropriately. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
5.
Innovative substructuring technique for hybrid simulation of multistory buildings through collapse 
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下载免费PDF全文 Hybrid simulation combines numerical and experimental methods for cost‐effective, large‐scale testing of structures under simulated dynamic earthquake loads. Particularly for experimental seismic collapse simulation of structures, hybrid testing can be an attractive alternative to earthquake simulators due to the limited capacity of most facilities and the difficulties and risks associated with a collapsing structure on a shaking table. The benefits of hybrid simulation through collapse can be further enhanced through accurate and practical substructuring techniques that do not require testing the entire structure. An innovative substructuring technique for hybrid simulation of structures subjected to large deformations is proposed to simplify the boundary conditions by overlapping the domains between the numerical and experimental subassemblies. The advantages of this substructuring technique are the following: it requires only critical components of the structure to be tested experimentally; it reduces the number of actuators at the interface of the experimental subassemblies; and it can be implemented using typically available equipment in laboratories. Compared with previous overlapping methods that have been applied in hybrid simulation, this approach requires additional sensing in the hybrid simulation feedback loop to obtain internal member forces, but provides significantly better accuracy in the highly nonlinear range. The proposed substructuring technique is verified numerically and validated experimentally, using the response of a four‐story moment‐resisting frame that was previously tested to collapse on an earthquake simulator. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This paper presents a new analytical model for describing the large rocking response of an elastic multi‐mass structure resting on ideally rigid ground. Using the experimental results from a rocking steel column, the ability of the proposed analytical model to estimate the rocking and translational acceleration response under free vibration, pulse and earthquake excitations is evaluated. It is observed that the classical treatment of impact may result in an unrealistically large transfer of energy to vibrations. Therefore a new Dirac‐delta type impact model that spreads the effects of impact over time and space is proposed. The use of a Dirac‐delta model and accurate restitution factors play a pivotal role in prediction of rocking and acceleration responses. In order to characterize the nonlinear response better, a modal analysis of the linearized system is proposed. With this approach, the vibration mode frequencies and shapes during rocking action were determined. A comparison of analytical and experimental modal estimations suggests good agreement. The results emphasize that the vibration characteristics of several vibration modes are affected by rocking action, and these modes may be excited at impact. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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This paper presents a statistical performance analysis of a semi‐active structural control system for suppressing the vibration response of building structures during strong seismic events. The proposed semi‐active mass damper device consists of a high‐frequency mass damper with large stiffness, and an actively controlled interaction element that connects the mass damper to the structure. Through actively modulating the operating states of the interaction elements according to pre‐specified control logic, vibrational energy in the structure is dissipated in the mass damper device and the vibration of the structure is thus suppressed. The control logic, categorized under active interaction control, is defined directly in physical space by minimizing the inter‐storey drift of the structure to the maximum extent. This semi‐active structural control approach has been shown to be effective in reducing the vibration response of building structures due to specific earthquake ground motions. To further evaluate the control performance, a Monte Carlo simulation of the seismic response of a three‐storey steel‐framed building model equipped with the proposed semi‐active mass damper device is performed based on a large ensemble of artificially generated earthquake ground motions. A procedure for generating code‐compatible artificial earthquake accelerograms is also briefly described. The results obtained clearly demonstrate the effectiveness of the proposed semi‐active mass damper device in controlling vibrations of building structures during large earthquakes. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Real‐time hybrid testing combines experimental testing and numerical simulation, and provides a viable alternative for the dynamic testing of structural systems. An integration algorithm is used in real‐time hybrid testing to compute the structural response based on feedback restoring forces from experimental and analytical substructures. Explicit integration algorithms are usually preferred over implicit algorithms as they do not require iteration and are therefore computationally efficient. The time step size for explicit integration algorithms, which are typically conditionally stable, can be extremely small in order to avoid numerical stability when the number of degree‐of‐freedom of the structure becomes large. This paper presents the implementation and application of a newly developed unconditionally stable explicit integration algorithm for real‐time hybrid testing. The development of the integration algorithm is briefly reviewed. An extrapolation procedure is introduced in the implementation of the algorithm for real‐time testing to ensure the continuous movement of the servo‐hydraulic actuator. The stability of the implemented integration algorithm is investigated using control theory. Real‐time hybrid test results of single‐degree‐of‐freedom and multi‐degree‐of‐freedom structures with a passive elastomeric damper subjected to earthquake ground motion are presented. The explicit integration algorithm is shown to enable the exceptional real‐time hybrid test results to be achieved. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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台站设备故障响应和风险排除是地震监测工作的基本内容,针对其便捷性和高时效性要求,采用Java语言,开发基于Android平台的地震地球物理数据监控软件。该软件整合重庆市地震局监测工作中的各项业务需求,采用云服务、Tomcat服务器及百度地图等技术,实现了数据实时查看及历史数据波形浏览等功能,及时获取仪器设备工作状态,及时发现设备故障并进行维护,工作效率得以提高。 相似文献
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Evaluation of the structural damage of high‐rise reinforced concrete buildings using ambient vibrations recorded before and after damage 下载免费PDF全文
下载免费PDF全文 Hirotoshi Uebayashi Masayuki Nagano Takenori Hida Takehiko Tanuma Mitoshi Yasui Shigeki Sakai 《地震工程与结构动力学》2016,45(2):213-228
Evaluation of the degrees of structural damage suffered by high‐rise residential buildings after being subjected to strong ground motions is extremely important to the development of life continuity planning for building residents. However, these evaluations cannot be based on strong‐motion records alone, because earthquake observation equipment is not installed in most such buildings in Japan. In this study, we propose simple equations for estimating the stiffness degradation rate and the peak inter‐story drift ratio (PIDR) by using ambient vibration records instead of strong‐motion records when high‐rise RC buildings are subjected to a severe earthquake. More specifically, we propose one equation that relates the square root of the stiffness degradation rate, which is the ratio of natural frequencies at the maximum response to the preliminary tremor response (elastic state), in strong‐motion records with the ratio of natural frequencies identified from ambient vibrations before and after damage was suffered. We also propose an equation that relates the PIDR with the stiffness degradation rate on the basis of the stiffness‐degrading bilinear restoring force characteristic derived from the strong‐motion records of 13 high‐rise buildings for the 1995 Hyogoken‐Nanbu Earthquake (Mw 6.9) and the 2011 Tohoku‐Oki Earthquake (Mw 9.0). Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
12.
A hybrid control platform is investigated in this paper to mitigate microvibrations to a group of vibration-sensitive equipment installed in a microelectronics facility subject to nearby road vehicle-induced horizontal and vertical ground motions. The hybrid control platform, on which microelectronics equipment is installed, is mounted on a building floor through a series of passive mounts and controlled by hydraulic actuators in both horizontal and vertical directions. The control platform is an elastic body with significant bending modes of vibration, and a sub-optimal control algorithm is used to manipulate the hydraulic actuators with actuator dynamics included. The finite element model and the equations of motion of the coupled platform-building system are then established in the absolute coordinate to facilitate the feedback control and performance evaluation of the platform. The horizontal and vertical ground vibrations at the base of the building induced by nearby moving road vehicles are assumed to be stationary random processes. A typical three-story microelectronics building is selected as a case study. The case study shows that the vertical vibration of the microelectronics building is higher than the horizontal. The use of a hybrid control platform can effectively reduce both horizontal and vertical microvibrations of the microelectronics equipment to the level which satisfies the stringent microscale velocity requirement specified in the Bolt Beranek & Newman (BBN) criteria. 相似文献
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A simple analytical procedure is developed for calculating the seismic energy dissipated by a linear SDOF system under an earthquake ground excitation. The ground excitation is specified by its pseudo-velocity spectra and effective duration whereas the SDOF system is defined by its natural period of vibration and viscous damping ratio. However, the derived relationship for the energy dissipation demand under an earthquake excitation is sensitive neither to the viscous damping ratio nor the ductility ratio when the SDOF system undergoes inelastic response. Accordingly, the proposed relationship can be employed in an energy-based seismic design procedure for determining the required energy dissipation capacity of a structural system. 相似文献
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在地震作用下,抗震支吊架理应保障建筑机电工程设施和管道系统均具备良好的服役性能。因此,对抗震支吊架的抗震性能进行检测至关重要。本文以某典型地下室抗震支吊架为对象开展了顺管向地震模拟振动台试验,通过多工况试验对比分析了不同支吊架的位移和加速度的地震响应。试验结果表明:抗震支吊架显著降低了管道位移,减振率最高可达到96%,但对于加速度响应的抑制作用较小。易损性分析表明:采用成品支吊架时,管道系统在遭受相当于设防烈度的地震作用时会发生严重损伤,而采用抗震支吊架的管道系统能够保全其功能。 相似文献
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Real‐time distributed hybrid testing: coupling geographically distributed scientific equipment across the Internet to extend seismic testing capabilities 下载免费PDF全文
下载免费PDF全文 Martin S. Williams Matt S. Dietz Anthony Blakeborough Ignacio Lamata Martínez 《地震工程与结构动力学》2014,43(7):1023-1043
Large‐scale testing and qualification of structural systems and their components is crucial for the development of earthquake engineering knowledge and practice. However, laboratory capacity is often limited when attempting larger experiments due to the sheer size of the structures involved. To overcome traditional laboratory capacity limitations, we present a new earthquake engineering testing method: real‐time distributed hybrid testing. Extending current approaches, the technique enables geographically distributed scientific equipment including controllers, dynamic actuators and sensors to be coupled across the Internet in real‐time. As a result, hybrid structural emulations consisting of physical and numerical substructures need no longer be limited to a single laboratory. Larger experiments may distribute substructures across laboratories located in different cities whilst maintaining correct dynamic coupling, required to accurately capture physical rate effects. The various aspects of the distributed testing environment have been considered. In particular, to ensure accurate control across an environment not designed for real‐time testing, new higher level control protocols are introduced acting over an optimised communication system. New large time‐step prediction algorithms are used, capable of overcoming both local actuation and distributed system delays. An overview of the architecture and algorithms developed is presented together with results demonstrating a number of current capabilities. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Following the severe earthquake damage at San Fernando in 1971, it became of technical and perhaps psychological importance to demonstrate that properly re-designed electrical equipment is able to withstand even worse transient vibration phenomena which can be produced in an earthquake simulator laboratory. This has been accomplished for one column of a 500 kV gas circuit breaker and the test results are used to qualify the much larger original 3-column assembly by means of a computer-aided structural analysis. Since the equipment exhibited some closely spaced, cross-coupled modes of vibration, a valuable comparison could be obtained between the effects produced by El Centro 1940 ground acceleration and those for a more purposeful sine beat vibration input. The latter can be adjusted to produce definite stresses and fatigue effects in specific parts of the equipment due to quasi-resonance response. 相似文献
17.
弦支穹顶结构动力反应分析 总被引：1，自引：0，他引：1
以天津开发区商务中心大堂的弦支穹顶为研究对象,分析了弦支穹顶结构体系的自振特性,分别运用随机模拟风振分析方法和时间历程分析方法,对其进行了风振和地震反应分析,得到了结构在动力荷载作用下的响应时程,并对分析结果进行了频谱分析和统计分析。研究发现弦支穹顶结构的自振频率呈密集型分布,且振型复杂;结构的风振响应基本以受迫振动为主,没有出现明显的峰值共振现象;结构的地震响应在前几阶基频处出现了较为明显的峰值共振现象;从振动的幅值角度看,风荷载的动力作用效应相对于地震荷载要显著。 相似文献
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This paper presents the results of an experimental and analytical/computational study of the performance of multi‐unit particle dampers with an MDOF system. A series of shaking table tests of a three‐storey steel frame with the particle damper system were carried out to evaluate the performance of the system and to verify the analysis method. An analytical solution based on the discrete element method is also presented. A comparison between the experimental and computational results shows that reasonably accurate estimates of the response of a primary system under earthquake excitations can be obtained. These results also indicate that the excitation characterization influences the performance of the particle damper system, for example, particle dampers have good performance in reducing the seismic response of structures and particle movements of plug flow pattern can yield good vibration attenuation effects. It is shown that by using properly designed multi‐unit particle dampers, a lightly damped primary system can achieve a reasonable reduction in its response, with a small weight penalty. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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导管架式海洋平台结构阻尼隔振体系及其减振效果分析 总被引：10，自引：2，他引：10
导管架式海洋平台结构是当前应用最广的一种平台结构形式。本文研究导管架式海洋平台结构阻尼隔振体系及其减振效果。针对导管架式海洋平台结构的型式与特点，为了充分发挥阻尼器的耗能减振作用，提出了在平台结构导管架端帽和甲板之间设置柔性阻尼层的新型阻尼隔振方案。针对渤海JZ20－2MUQ平台结构，建立了海洋平台结构阻尼隔振体系简化计算模型，研究了隔振层参数与结构阻尼比的关系以及它们对结构整体和隔振层层间相对位移的控制效果；进行了多种冰荷载工况和地震工况的数值模拟。结果表明，阻尼隔振方案是导管架式海洋平台结构的一种有效的减振措施。 相似文献