Negative stiffness device for seismic protection of smart base isolated benchmark building

Sun, Tiecheng; Lai, Zhilu; Nagarajaiah, Satish; Li, Hong‐Nan

doi:10.1002/stc.1968

Cited by 79 publications

(30 citation statements)

References 19 publications

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“…The gap spring is adopted to help the NSD engaging at a prescribed displacement to simulate a bilinear‐elastic behavior. In the meantime, further research extended to other passive NSD configurations such as the NSD using precompressed spring and ramps, the NSD using precompressed spring and templates, and the NSD using pretorqued torsional springs and gearwheels . In 2015, Shi and coworkers proposed and systematically studied a magnetic negative stiffness damper, which utilizes the attraction effect of permanent magnets.…”

Section: Introductionmentioning

confidence: 99%

Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Wang

Sun

Nagarajaiah

2019

Structural Design Tall Build

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SUMMARY This paper presents a study on multi‐degree‐of‐freedom (MDOF) structures equipped with a negative stiffness amplifying damper (NSAD). The NSAD not only preserves the negative stiffness feature of negative stiffness devices (NSDs) but also achieves prominent damping magnification effect, substantially reducing a NSD's requirement for high additional damping, which is used to contain the increased displacements resulting from the reduction in overall stiffness of a system. The dynamic equations of MDOF systems with NSADs are described in state–space representation, and the effective damping and frequencies are parametrically studied. Then, a simple optimization method is proposed. A study of the 20‐storey benchmark building shows that NSADs are the most efficient of supplemental devices in reducing interstorey drifts compared with viscous dampers (VDs) and viscoelastic dampers (VEDs) with the same supplemental damping coefficient. For instance, when compared with that of VEDs, the maximal peak interstorey of NSADs can be further reduced by about 30%. In terms of reducing acceleration responses, NSADs perform much better than VDs and VEDs owing to their negative stiffness feature. Partially arranged, NSADs are best implemented at the storeys that have smaller interstorey drift responses. This is because the negative stiffness preserved by NSADs significantly reduces the interstorey drift of storeys without NSADs.

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Section: Introductionmentioning

confidence: 99%

Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Wang

Sun

Nagarajaiah

2019

Structural Design Tall Build

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“…As can be seen in Figure (left), some cases require negative stiffness; these cases correspond to nonpassive devices. This can be achieved by a passive negative stiffness device() or in case of the rolling isolation system by a variable shape profile() or stiffness. () As the displacement‐to‐acceleration weight ratio increases, the required stiffness and damping increase.…”

Section: Numerical Exploration Of Free Responsesmentioning

confidence: 99%

Enhanced passive control of dual‐mode systems under extreme seismic loading: An optimal control approach

Tehrani

Harvey

2019

Struct Control Health Monit

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Devastating economic losses can arise from damage to mission-critical facilities, structures, and systems supporting vital equipment (systems in general). One of the sources of damages to such systems is displacements in excess of the displacement capacity. The increase in displacement demand is more pronounced in systems located on soft soils 1-3 or when they are exposed to long-period seismic loadings or near-fault excitations with large pulse duration. 4,5 Exceeding the displacement capacity results in the pounding between adjacent structures or the impact in system's components. [6][7][8] Pounding/impact produces harmful undesired transmitted acceleration to the system, [9][10][11][12] which is detrimental for acceleration sensitive components.The most straightforward solution to mitigate impact is to increase the displacement capacity. However, it is not always possible to increase the displacement capacity because of environmental limitations or cost prohibitions, in both new construction and retrofit of an existing structure. 8,9 In the literature, different solutions for pounding mitigation have been proposed and assessed. One method is to connect adjacent structures at some specific locations. These connections enforce the adjacent structures to have in-phase motions with one another. [13][14][15] For instance, the use of hard rubber bumpers or stiff linking between the segments of a bridge can improve the bridge behavior during severe earthquakes 13 or inserting a shock-absorbing material such as rubber for pounding mitigation in buildings. 8 Alternatively, a pair of pressurized fluid-viscous dissipaters was used for pounding mitigation between a church structure and its bell tower. 7 Applying a similar concept, a share tuned mass damper between two adjacent tall buildings can reduce both structural responses and the probability of pounding. 14 Others have shown that using links such as springs, dashpots, or viscoelastic elements between two adjacent three-story buildings can significantly reduce the gap size and prevent pounding. 15 Another solution to this problem is to reduce the displacement demand via some energy dissipative mechanisms, which has been studied extensively. For instance, increasing the damping in an isolation system reduces the isolator displacement and base shear. [16][17][18] Approaches based on semi-active control have also been developed to decrease structural displacement. 19 Recently, inerters have been shown to be effective for response reduction as well. 20,21 Although the above-mentioned solutions have shown to be effective, there are some drawbacks with these approaches, and several studies showed that devastating damage to systems has been observed under high-amplitude seismic loadings, even with the presence of some energy dissipative mechanisms. 4,7,17 One of the disadvantages of connecting adjacent structures is the impairing of the dynamics of each individual structures. In addition, reducing the displacement demand comes at the expense of increasing the total transfer...

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“…Among them, passive supplemental damping systems have been widely accepted by the structural engineering field due to their demonstrated long term reliability and cost-effectiveness [2,3,4]. Examples of passive devices include viscous dampers [5,6], viscoelastic dampers [7,8], metallic and friction dampers [9,10,11], tuned mass/fluid dampers [12,13,14], and base isolation systems [15,16,17].…”

Section: Introductionmentioning

confidence: 99%

Numerical evaluation of a novel passive variable friction damper for vibration mitigation

Barzegar

Laflamme

Downey

et al. 2020

Engineering Structures

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This study assesses the performance of a novel passive variable friction damper (PVFD) at mitigating wind-and seismic-induced vibrations. The PVFD consists of two friction plates upon which a cam profile modulates the normal force as a function of its rotation. A unique feature of the PVFD is its customizable shape, yielding a customizable friction hysteresis. The objective of the study is to assess the benefits of crafting the friction behavior to satisfy motion criteria. This is done numerically on two example buildings: a 5-story structure subjected to seismic loads, and a 20-story structure subjected to non-simultaneous seismic and wind loads. A probabilistic performance-based design procedure is introduced to select the optimum cam configurations throughout each building under the design loads. After that, numerical simulations are conducted to compare their performance against that of two equivalent damping schemes: viscous dampers and passive friction dampers. Results show that customization of the hysteresis behaviors throughout a structure is necessary to yield optimal performance. Also, the PVFD outperforms the other damping schemes for wind mitigation by yielding a more stable response in terms of lower accelerations over the entire wind event. Under seismic loads, all three damping schemes exhibited comparable performance, but the PVFD yielded a significantly more uniform drift for the 20-story building.

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Negative stiffness device for seismic protection of smart base isolated benchmark building

Cited by 79 publications

References 19 publications

Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

Enhanced passive control of dual‐mode systems under extreme seismic loading: An optimal control approach

Numerical evaluation of a novel passive variable friction damper for vibration mitigation

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