Nonlinear earthquake response of structurally interconnected buildings

1992 ◽  
Vol 19 (4) ◽  
pp. 560-572 ◽  
Author(s):  
André Filiatrault ◽  
Bryan Folz
Keyword(s):  
Seismic Event ◽  
Ground Motions ◽  
Time History ◽  
Earthquake Response ◽  
Historical Earthquake ◽  
Friction Damping ◽  
Building Models ◽  
Coupled Structures ◽  
Nonlinear Time History ◽  
Damping Capability

This paper evaluates the performance of closely spaced plane steel framed buildings interconnected by horizontal structural links to prevent pounding during earthquake excitations. Friction damping capability is incorporated into the modelling of these structural links in order to also determine their potential for dissipating energy during a seismic event. Six pairs of building models, having widely different dynamic characteristics, are considered in this investigation. A parametric study, utilizing nonlinear time-history dynamic analysis, is performed to determine the optimum properties for the structural links when each building pair is excited by three different historical earthquake ground motions. This is followed by a detailed reponse analysis comparison of each of these optimized friction damped coupled structures against their uncoupled and elastically coupled counterparts. Key words: earthquake, steel, frames, inelastic, pounding, friction, damping.

Seismic response analysis of steel–concrete hybrid wind turbine tower

2021 ◽  
pp. 107754632110075
Author(s):  
Junling Chen ◽  
Jinwei Li ◽  
Dawei Wang ◽  
Youquan Feng
Keyword(s):  
Wind Turbine ◽  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Seismic Action ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Wind Turbine Tower ◽  
Ground Types ◽  
Nonlinear Time History

The steel–concrete hybrid wind turbine tower is characterized by the concrete tubular segment at the lower part and the traditional steel tubular segment at the upper part. Because of the great change of mass and stiffness along the height of the tower at the connection of steel segment and concrete segment, its dynamic responses under seismic ground motions are significantly different from those of the traditional steel tubular wind turbine tower. Two detailed finite element models of a full steel tubular tower and a steel–concrete hybrid tower for 2.0 MW wind turbine built in the same wind farm are, respectively, developed by using the finite element software ABAQUS. The response spectrum method is applied to analyze the seismic action effects of these two towers under three different ground types. Three groups of ground motions corresponding to three ground types are used to analyze the dynamic response of the steel–concrete hybrid tower by the nonlinear time history method. The numerical results show that the seismic action effect by the response spectrum method is lower than those by the nonlinear time history method. And then it can be concluded that the response spectrum method is not suitable for calculating the seismic action effects of the steel–concrete hybrid tower directly and the time history analyses should be a necessary supplement for its seismic design. The first three modes have obvious contributions on the dynamic response of the steel–concrete hybrid tower.

Influence of Earthquake Attack Angle on Seismic Demands for Structures under Bi-Directional Ground Motions

2011 ◽  
Vol 255-260 ◽  
pp. 2330-2334 ◽  
Author(s):  
Yu Zhang ◽  
Quan Wang Li ◽  
Jian Sheng Fan
Keyword(s):  
Seismic Design ◽  
Ground Motions ◽  
Time History ◽  
Earthquake Excitation ◽  
Seismic Demands ◽  
3 Dimensional ◽  
Nonlinear Time History Analyses ◽  
Modification Factor ◽  
Structural Responses ◽  
Nonlinear Time History

The earthquake may attack the structural building from any angle, but in current seismic design codes, this type of uncertainty is seldom accounted. The uncertainty associated with the direction of earthquake excitation was considered in this paper, and its effect on structural responses was investigated. For this purpose, a simple 3-dimensional model with symmetric plan was established, which had fundamental periods ranged from 0.1s to 5.0s, and was subjected to a set of 30 ground motion pairs for which both linear and nonlinear time history analyses were performed. Analyzing results showed that, on average, the elastic roof acceleration is 32% underestimated, and the inelastic roof displacement is 18% underestimated if the variation of earthquake excitation direction is not consider. Recognizing this, a modification factor for the seismic demand was proposed thorough a statistical analysis, which guarantees a probability of 95% design safety

The Application of E Shaped Steel Bearing on the Simply Supported Beam Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 3141-3144
Author(s):  
Ling Jun Kong ◽  
Yan Bei Chen ◽  
Jun Liu ◽  
Qi Bin Jiang
Keyword(s):  
Computational Models ◽  
Time History ◽  
Earthquake Response ◽  
Bending Moments ◽  
Shear Forces ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Related Data ◽  
Nonlinear Time History ◽  
Beam Bridge

To study the application of E shaped steel bearing on the simply supported beam bridge, the Xinhua bridge is analyzed by the nonlinear time-history method and the Midas/Civil software, considering the interaction between pile and soil. The related data are obtained through two computational models. And the data are compared in this paper. The results show that the bending moments and shear forces of the bottom of the fixed pier are reduced, due to using the E shaped steel bearing at the fixed pier. The E shaped steel bearing dissipates the earthquake energy and reduces the earthquake response of the bridge.

scholarly journals Isolating system using U Shaped steel damper

2021 ◽  
Vol 309 ◽  
pp. 01136
Author(s):  
Siripuram Vamshisheela ◽  
Atulkumar Manchalwar
Keyword(s):  
Base Isolation ◽  
Ground Motions ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Base Shear ◽  
Energy Device ◽  
History Analysis ◽  
Structural Responses ◽  
Nonlinear Time History ◽  
Story Building

In this work the performance of U-Shaped Steel Isolator is evaluated for a 5-story building subjected to seismic and blast vibrations. The structure is analysed using SAP 2000 software and a nonlinear time history analysis is carried out. The effectiveness of using base isolation is studied by comparing the structural responses of the building with isolator and without isolator and noticeable difference was observed. As the U-Shaped isolator absorbs the energy in all directions, it effectively controls the structural responses. In this study, the building is subjected to four different seismic and four different blast induced ground motions. It was observed that by the use of supplementary energy device there is reduction in top story acceleration, base shear and less deformation in the structure. This study concludes that the use of isolator has been effective in minimizing structural responses.

HHT-BASED SIMULATION OF UNIFORM HAZARD GROUND MOTIONS

2009 ◽  
Vol 01 (01) ◽  
pp. 71-87 ◽  
Author(s):  
Y. K. WEN ◽  
PING GU
Keyword(s):  
Los Angeles ◽  
Ground Motions ◽  
Time History ◽  
Simulation Method ◽  
Nonlinear Time History Analysis ◽  
Rupture Directivity ◽  
Regional Seismicity ◽  
Hilbert Huang Transform ◽  
History Analysis ◽  
Nonlinear Time History

Hilbert–Huang Transform (HHT) is a new analysis method for nonstationary and nonlinear signals. A simulation method based on HHT is used to generate uniform hazard ground motions, which are often needed for nonlinear time history analysis for structures in high-seismic zones. The HHT-based simulation method can reproduce the amplitude and frequency content change with time for nonstationary random processes, thus is very suitable for the simulation of earthquake ground motions, especially the near-fault ground motions with long-period pulses. Monte-Carlo method and historical earthquake records are used for the generation of a large pool of ground motions, from which the uniform hazard ground motions are selected. The regional seismicity and rupture directivity are considered. An example is given of a site near Los Angeles City Hall. The advantages and difficulties of the proposed method are also discussed.

Plastic Analysis on Buckling Restrained Braced Steel Frame

2013 ◽  
Vol 859 ◽  
pp. 157-162
Author(s):  
Xue Zou ◽  
Jun Zhao ◽  
En He Bao ◽  
Yi Hu Chen
Keyword(s):  
Parametric Analysis ◽  
Main Parameter ◽  
Plastic Hinge ◽  
Time History ◽  
Steel Frame ◽  
Buckling Restrained Brace ◽  
Participation Ratio ◽  
Building Models ◽  
Nonlinear Time History Analyses ◽  
Nonlinear Time History

Six pieces of building models were designed for studying the multilayer buckling restrained braced steel frame in this paper. The main parameter in the study included the frame strength and the level Participation ratio β. Second-order nonlinear time history analyses for models are conducted based on plastic hinge theory. The parametric analysis was performed on story displacement and shear. The results revealed that story bending deformation become more remarkable when the frame strength is increasing from 0.3 to 0.5 or the level Participation ratio β from 30% to 90%, and this situation is more obvious on the upper layer. The share of shear by the buckling restrained brace and the largest story shear ratio get larger in these models as the frame strength and the level Participation ratio β increasing.

scholarly journals Inelastic demand spectra for bi-linear seismic isolation systems based on nonlinear time history analyses and the response of lead-rubber bearing isolation systems subjected to near-source ground motions

2007 ◽  
Vol 40 (1) ◽  
pp. 7-17 ◽  
Author(s):  
John X. Zhao ◽  
Jian Zhang
Keyword(s):  
Seismic Isolation ◽  
Ground Motions ◽  
Time History ◽  
Design Tool ◽  
Nonlinear Time History Analysis ◽  
Inelastic Demand ◽  
Isolated Structures ◽  
Seismically Isolated ◽  
Isolation Systems ◽  
Nonlinear Time History

In this study, we present an inelastic demand spectrum for the design of seismically-isolated structures using lead-rubber bearings or other types of isolators with bi-linear hysteresis loops and the inelastic spectrum can be used in the design of seismically-isolated structures in a very similar manner to capacity spectrum method. The inelastic demand spectrum is a very useful design tool for visual selection of optimal isolation parameters, and eliminates the use of equivalent linear-elastic substitute structures as the displacement demand is obtained from nonlinear time history analysis. The responses of seismically-isolated structures subjected to near-source ground motions with either large forward-directivity pulses or fault-fling pulses are presented. Our analyses suggest that seismic isolation can be used to protect structures subjected to recorded ground motions currently available to us, with acceptable levels of base shear coefficient and isolator displacement, except for one component of the TCU068 record from the 1999 Chichi, Taiwan, earthquake (which contained a large permanent displacement of nearly 10 m).

scholarly journals Deterministic Wind Load Dynamic Analysis of High Rise Steel Buildings Including P-Delta Effects

2019 ◽  
Vol 26 (1) ◽  
pp. 129-135
Author(s):  
Rafaa M. Abbas ◽  
Ahmed Sada Dheeb
Keyword(s):  
Time History ◽  
Wind Load ◽  
Steel Buildings ◽  
High Rise ◽  
Building Models ◽  
History Analysis ◽  
Nonlinear Time History Analyses ◽  
Steel Building ◽  
Linear And Nonlinear ◽  
Nonlinear Time History

This study concerns with the investigation of the second-order geometric nonlinearity effects of P-Delta analysis on the dynamic response of high rise steel buildings due to deterministic wind load. Linear and nonlinear time history analyses were conducted to analyze different tall steel building models adopted in the study. Five steel building models ranging from 10 to 50 stories were numerically modeled and analyzed using finite element code ETABS (version 16.0.3). Deterministic dynamic wind load per ASCE 7-10 is applied to the buildings as a main lateral load. Comparative study between linear and nonlinear time history analyses reveals that nonlinear time history analysis including P-Delta effects displayed larger values of buildings lateral sway than those of linear time history analysis. Generally, including P-Delta effect in the nonlinear analysis increases the flexibility of the building structure, and thus increases response peak values and that peak values occur at a longer time periods indicating lesser response oscillations. The study recommends that P-Delta effect need to be addressed by any dynamic wind analysis for tall steel buildings with 20 story height or more.

Evaluation of Out-of-Plane Wall Anchorage Force Provisions in Buildings with Rigid Walls and Flexible Roof Diaphragms

2017 ◽  
Vol 33 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Maria Koliou ◽  
John Lawson ◽  
Andre Filiatrault ◽  
Dominic J. Kelly
Keyword(s):  
Model Building ◽  
Ground Motions ◽  
Time History ◽  
Plane Wall ◽  
Dynamic Analyses ◽  
Out Of Plane ◽  
Current Design ◽  
Nonlinear Time History ◽  
Rigid Walls ◽  
Strong Ground

Heavy concrete and masonry walled buildings with lightweight steel or wood flexible roof diaphragms are a common type of construction in North America. Failures of the out-of-plane wall anchorage to these roof systems and the resulting partial roof collapses during past earthquakes have led to repeated revisions to the seismic design provisions in the U.S. model building codes. However, the force levels considered in the current design provisions have remained largely unchanged since their introduction in the 1997 Uniform Building Code, and these provisions have not been fully tested by strong ground motions in the field. Using a two dimensional numerical framework, a series of nonlinear time history dynamic analyses on various building archetypes were conducted to evaluate the validity of the current wall anchorage design force levels. The results of this study reveal that the current wall anchorage design forces are generally appropriate, but with some very significant exceptions.

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