Seismic performance of suspended‐floor structures with viscous dampers considering acceptable interstory drift

2021 ◽  
Author(s):  
Bin Zeng ◽  
Jingwei Gao ◽  
Yuan Qing ◽  
Chun‐Lin Wang ◽  
Xun Sun
Keyword(s):  
Seismic Performance ◽  
Viscous Dampers ◽  
Interstory Drift

Effects of Brace Stiffness and Nonlinearity of Viscous Dampers on Seismic Performance of Structures

2021 ◽  
pp. 2150188
Author(s):  
Siyuan Li ◽  
Yung-Tsang Chen ◽  
Y. H. Chai ◽  
Bo Li
Keyword(s):  
Seismic Performance ◽  
Structural Performance ◽  
Design Parameters ◽  
Viscous Dampers ◽  
Story Structure ◽  
Design Efficiency ◽  
Time Stepping ◽  
Seismic Hazard Mitigation ◽  
Method Effects ◽  
Supplemental Dampers

In the applications of supplemental dampers for seismic hazard mitigation, the supporting braces for the dampers are considered an important component for ensuring an efficient energy dissipation in the structure. Despite their importance, studies on the effects of the brace stiffness and the velocity exponent in the case of nonlinear viscous dampers are rather limited. In this paper, a numerical time-stepping method is developed for computing the seismic response of the structure with supporting braces and nonlinear viscous dampers. Using the proposed method, effects of the parameters of the nonlinear damper-brace systems are investigated, using first a single-story structure, followed by multi-story buildings. Results indicated that the design parameters for the dampers and supporting braces may be combined in numerous ways to satisfy a given set of structural performance objectives, but the brace stiffness can be minimized to achieve design efficiency in the range of velocity exponent commonly used for seismic applications of nonlinear viscous dampers. Results also indicated that for a set brace stiffness, if the dampers are optimally designed, the velocity exponent has an insignificant effect on the structural seismic performance objectives considered in this paper.

Seismic Performance of the Buckling-Restrained Brace Central Buckle for Long-Span Suspension Bridges

2018 ◽  
Vol 12 (05) ◽  
pp. 1850015 ◽  
Author(s):  
Wei Guo ◽  
Jianzhong Li ◽  
Nailiang Xiang
Keyword(s):  
Seismic Performance ◽  
Design Procedure ◽  
Suspension Bridges ◽  
Preliminary Design ◽  
Viscous Dampers ◽  
Buckling Restrained Brace ◽  
Long Span ◽  
Parametric Analyses ◽  
Yield Force ◽  
Central Buckle

In this paper, a novel central buckle composed of buckling-restrained braces (BRBs) is developed for long-span suspension bridges, and its preliminary design procedure is presented. Seismic performance of suspension bridges equipped with BRB central buckles is investigated and compared with those with conventional central buckles (e.g. rigid or flexible central buckles). Furthermore, the effect of BRB yield force, as well as the effectiveness of BRB central buckles combined with viscous dampers, is evaluated using parametric analyses. The results indicate that the BRB central buckle is more effective than other central buckles in reducing both the longitudinal girder displacements and force demands on towers during an earthquake. Furthermore, the combination of BRB central buckles and viscous dampers is a superior option for mitigating the seismic response of long-span suspension bridges.

Seismic performance analysis of Wenchuan Hospital structure with viscous dampers

2010 ◽  
Vol 19 (4) ◽  
pp. 397-419 ◽  
Author(s):  
Xue-Wei Chen ◽  
Jia-Xuan Li ◽  
Jack Cheang
Keyword(s):  
Performance Analysis ◽  
Seismic Performance ◽  
Viscous Dampers

Strengthening Research in the Longitudinal Frames of Prefabricated Structures with Viscous Dampers

2013 ◽  
Vol 671-674 ◽  
pp. 782-785
Author(s):  
Bin He ◽  
Jin Lai Pang ◽  
Cheng Qing Liu
Keyword(s):  
Seismic Performance ◽  
Pushover Analysis ◽  
Vertical Direction ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Viscous Dampers ◽  
Existing Building ◽  
Concrete Frame ◽  
Uniform Drift ◽  
Nonlinear Time History

For the lack of research in the longitudinal frame of prefabricated structure for its weak lateral stiffness, pushover analysis is conducted to evaluate the seismic performance of a fabricated concrete frame. Based on case study, the strengthening strategies with viscous dampers are analyzed. In view of the undesirable drift distribution and failure mode in the existing building, it is believed that arrangement of dampers should be designed to attain a uniform drift distribution. Based on the nonlinear time history analysis method, the strategy of damper allocation in vertical direction of the structure is investigated .Results indicate that a proper design might be attained based on the property of existing system, leading to a uniform drift distribution and better seismic performance.

Seismic Performance of Steel MRF Structures with Nonlinear Viscous Dampers from Real-Time Hybrid Simulations

2018 ◽  
Vol 763 ◽  
pp. 967-974 ◽  
Author(s):  
Bai Ping Dong ◽  
Richard Sause ◽  
James M. Ricles
Keyword(s):  
Real Time ◽  
Seismic Performance ◽  
Phase 1 ◽  
Base Shear ◽  
Viscous Dampers ◽  
Reduced Beam Section ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Two Phases ◽  
Steel Mrf

Real-time hybrid earthquake simulations (RTHS) were performed on steel moment-resisting frame (MRF) structures with nonlinear viscous dampers. The test structures for the RTHS contain a moment-resisting frame (MRF), a frame with nonlinear viscous dampers (DBF), and a gravity load system with associated seismic mass and gravity loads. The MRFs have reduced beam section beam-to-column connections and are designed for 100%, 75%, and 60%, respectively, of the base shear strength required by ASCE 7-10. RTHS were performed to evaluate the seismic performance of these MRF structures. Two phases of RTHS were conducted: (Phase-1) the DBF is the experimental substructure in the laboratory; and (Phase-2) the DBF with the MRF is the experimental substructure. Results from the two phases of RTHS are evaluated. The evaluation shows that the RTHS provide a realistic and accurate simulation of the seismic response of the test structures. The evaluation also shows that steel MRF structures designed with reduced strength and with nonlinear viscous dampers can have excellent seismic performance.

scholarly journals Shaking Table Test for Evaluating the Seismic Performance of Steel Frame Retrofitted by Buckling-Restrained Braces

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tingting Wang ◽  
Jianhua Shao ◽  
Chao Zhao ◽  
Wenjin Liu ◽  
Zhanguang Wang
Keyword(s):  
Seismic Performance ◽  
Shear Force ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Steel Frame ◽  
Shaking Table ◽  
Frame Structure ◽  
Acceleration Response ◽  
Buckling Restrained Brace ◽  
Interstory Drift

To investigate the seismic performance of buckling-restrained braces under the earthquake action, the shaking table test with a two-story 1/4 scale model is carried out for the ordinary pure steel frame and the buckling-restrained bracing steel frame with low-yield-point steel as the core plate. The failure modes, dynamic characteristics, acceleration response, interstory drift ratio, strain, shear force, and other mechanical properties of those two comparative structures subjected to different levels of seismic waves are mainly evaluated by the experiment. The test results show that under the action of seismic waves with different intensities, the apparent observations of damage occur in the pure frame structure, while no obvious or serious damage in the steel members of BRB structure is observed. With the increase in loading peak acceleration for the earthquake waves, the natural frequency of both structures gradually decreases and the damping ratio gradually increases. At the end of the test, the stiffness degradation rate of the pure frame structure is 11.2%, while that of the buckling-restrained bracing steel frame structure is only 5.4%. The acceleration response of the buckling-restrained bracing steel frame is smaller than that of the pure steel frame, and the acceleration amplification factor at the second story is larger than that at the first story for both structures. The average interstory drift ratios are, respectively, 1/847 and 1/238 for the pure steel frame under the frequent earthquake and rare earthquake and are 1/3000 and 1/314 for the buckling-restrained bracing steel frame, which reveals that the reduction rate of lateral displacement reaches a maximum of 71.71% after the installation of buckling-restrained brace in the pure steel frame. The strain values at each measuring point of the structural beam and column gradually increase with the increase of the peak seismic acceleration, but the strain values of the pure steel frame are significantly larger than those of the buckling-restrained bracing steel frame, which indicates that the buckling-restrained brace as the first seismic line of defense in the structure can dramatically protect the significant structural members. The maximum shear force at each floor of the structure decreases with the increase in height, and the shear response of the pure frame is apparently higher than that of the buckling-restrained bracing structure.

scholarly journals Assessing Seismic Performance of Gantry Crane Subjected to Near-Field Ground Motions Using Incremental Dynamic and Endurance Time Analysis Methods

2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Qihui Peng ◽  
Wen-ming Cheng ◽  
Peng Guo ◽  
Hongyu Jia
Keyword(s):  
Seismic Performance ◽  
Incident Angle ◽  
Ground Motions ◽  
Near Field ◽  
Maxwell Model ◽  
Element Model ◽  
Gantry Crane ◽  
Time Analysis ◽  
Viscous Dampers ◽  
Endurance Time

Assessing the seismic performance of the gantry crane is significant since the structure is more vulnerable to earthquakes with the increase in size and lifting weight capacity. This paper aims to investigate the seismic response of the gantry crane incorporating near-field ground motions using incremental dynamic and endurance time analysis (IDA and ETA) methods. To model the structure accurately, a nonlinear finite element model of the gantry crane considering the viscoelastic effect is developed in the OpenSees platform. Then, the IDA method is also carried out for a comparison with the ETA method. The results of the two methods are consistent with a correlation of 93.9% while the computational demand of the ETA method is much less than those of the IDA method. To study further, both the seismic incident angle and the application of viscous dampers using the Maxwell model are analyzed and discussed in detail. The results show that seismic incident angle has a distinct influence on the maximum seismic displacement and viscous dampers can significantly reduce the seismic demand of the gantry crane. These findings support the seismic design of gantry cranes and evaluate the structural seismic performance efficiently.

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