Interface friction effects on scaling a vertical spring-viscous damper isolation system in a shaking table test

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 1878-1891
Author(s):  
Shanshan Li ◽  
Ping Xiang ◽  
Biao Wei ◽  
Chengjun Zuo ◽  
Lizhong Jiang ◽  
...  
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Viscous Damper ◽  
Isolation System ◽  
Interface Friction

Shaking Table Test Study on Mid-Story Isolation Structures with Viscous Damper

2012 ◽  
Vol 226-228 ◽  
pp. 1149-1152
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Xiang Yun Huang
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Viscous Damper ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with linear natural rubber bearing and viscous damper are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

Shaking Table Test Study on Mid-Story Isolation Structures

2012 ◽  
Vol 446-449 ◽  
pp. 378-381
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Yu Hong Ma ◽  
Chao Yong Shen
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Lead Rubber Bearing ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with lead rubber bearing are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

scholarly journals Experimental Investigation on Semi-Active Control of Base Isolation System Using Magnetorheological Dampers for Concrete Frame Structure

2019 ◽  
Vol 9 (18) ◽  
pp. 3866 ◽  
Author(s):  
Weiqing Fu ◽  
Chunwei Zhang ◽  
Mao Li ◽  
Cunkun Duan
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Active Control ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Mr Damper ◽  
Shaking Table ◽  
Engineering Practice ◽  
Isolation System ◽  
Large Earthquakes

The traditional passive base isolation is the most widely used method in the engineering practice for structural control, however, it has the shortcoming that the optimal control frequency band is significantly limited and narrow. For the seismic isolation system designed specifically for large earthquakes, the structural acceleration response may be enlarged under small earthquakes. If the design requirements under small earthquakes are satisfied, the deformation in the isolation layer may become too large to be accepted. Occasionally, it may be destroyed under large earthquakes. In the isolation control system combined with rubber bearing and magnetorheological (MR) damper, the MR damper can provide instantaneous variable damping force to effectively control the structural response at different input magnitudes. In this paper, the control effect of semi-active control and quasi-passive control for the isolation control system is verified by the shaking table test. In regard to semi-active control, the linear quadratic regulator (LQR) classical linear optimal control algorithm by continuous control and switch control strategies are used to control the structural vibration response. Numerical simulation analysis and shaking table test results indicate that isolation control system can effectively overcome the shortcoming due to narrow optimum control band of the passive isolation system, and thus to provide optimal control for different seismic excitations in a wider frequency range. It shows that, even under super large earthquakes, the structure still exhibits the ability to maintain overall stability performance.

Seismic Performance of Guideway Sliding Isolator with Gap Springs for Precision Machinery

2008 ◽  
Vol 11 (5) ◽  
pp. 511-524
Author(s):  
George C. Yao ◽  
Wen-Chun Huang ◽  
Fan-Ru Lin
Keyword(s):  
Shaking Table Test ◽  
Model Simulation ◽  
Shaking Table ◽  
Viscous Damping ◽  
Far Field ◽  
Seismic Excitations ◽  
Isolation System ◽  
Near Fault ◽  
Seismic Motion ◽  
Nonlinear Performance

The performance of gap springs in a guideway sliding isolator (GSI) system developed to protect precision machinery against seismic motion has been studied. A spring is initially distanced from the system by a gap, causing the isolation system to exhibit nonlinear performance once the gap is closed, reducing the chance of resonance. A full-scale shaking table test of a 22-ton specimen and a numerical model simulation in SAP2000 have been performed. The study shows that springs possessing the appropriate gaps are more effective in controlling relative displacements than is a pure friction system. The optimal gap for a system subjected to far-field earthquakes was found to be 5mm. In addition, supplemental viscous damping of less than 15% of the critical damping had no significant effect on the GSI system far-field seismic response, but it did reduce the relative displacements of the system for near-fault seismic excitations.

Comparative Study on Nonlinear Earthquake Response of Girder Isolated Bridges with LRB and Model Shaking Table Test

2013 ◽  
Vol 706-708 ◽  
pp. 472-477
Author(s):  
Jie Dong Zhan ◽  
Xin Tong Li ◽  
Yang Li
Keyword(s):  
Seismic Response ◽  
Shaking Table Test ◽  
Experimental Results ◽  
Shaking Table ◽  
Vertical Force ◽  
Isolation System ◽  
Nonlinear Seismic Response ◽  
Girder Bridges ◽  
Deformation Properties ◽  
Rubber Bearings

Abstract: The thesis is aimed to study the characteristics nonlinear seismic response of the isolated continuous girder bridges with LRB. Inorder to achieve the aim, force- deformation properties of the LRB is considered as bilinear first, the bouc-wen model is adopted to imitate the force nonlinear deformation behavior of LRB, and by using Finite element method, the motion equation of the Isolation system of continuous girder bridge is established, then some shaking table tests towards the model of isolated continuous girder bridges with LRB is done. On this basis of it, by comparing the experimental results and calculation results, such as the acceleration and displacement of deck, vertical force of bearing, and the relationship between the Isolation layer displacement and the Level force displacement of the Bearing, we can see that the difference between the analytical results and the experimental results are very small. The results show that the calculation method can analyze Nonlinear Seismic Response of isolated continuous girder bridges with LRB efficiently. But when the vertical earthquake component is larger ,whether the results of the Vertical tension are produced or not, designing the Rubber bearings should be considered.

Study on a Simple Self-Resetting Sliding Isolation

2011 ◽  
Vol 250-253 ◽  
pp. 2558-2561
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Yu Hong Ma ◽  
Xue Zhen Zhuang ◽  
Chao Yong Shen
Keyword(s):  
Theoretical Analysis ◽  
Shaking Table Test ◽  
Masonry Structure ◽  
Brick Masonry ◽  
Shaking Table ◽  
Isolation System ◽  
Rubber Bearing ◽  
Sliding Isolation

This paper presents a simple Self-resetting sliding isolation system, which is composed of graphite sliding device and simple rubber bearing. Theoretical analysis is carried out. Shaking table test for a typical brick masonry structure in village of China is performed on a 1:4 scale. Results show that the proposed new isolation system can achieve a favorable level of performance.

Shaking Table Test Study on Seismic Responses of Base-Isolated Buildings under Near-Fault Ground Motions

2014 ◽  
Vol 1020 ◽  
pp. 457-462
Author(s):  
Miao Han ◽  
Yan Ling Duan ◽  
Huan Sun
Keyword(s):  
Shaking Table Test ◽  
Ground Motions ◽  
Shaking Table ◽  
Scale Model ◽  
Seismic Responses ◽  
Velocity Pulse ◽  
Isolation System ◽  
Near Fault ◽  
Test Study ◽  
Isolated Structures

The shaking table tests of a 1:7 scale model of three-floor steel frame base-isolated building was completed to study the seismic responses of base-isolated buildings under near-fault ground motions. Under the action of the typical near-fault seismic wave, the seismic responses of base-isolated structures increase with the increase of PGA. The maximum story displacements of super-structure decrease with increase of story. The velocity pulse has an adverse effect to acceleration responses of base-isolated structures. The isolation effect of base-isolated super-structures is still favorable under near-fault ground motions, but it will be necessary to add damping in isolation system or limit the displacement of bearings to prevent the excessive deformation of isolation layer.

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