scholarly journals Seismic Response of Plan-Asymmetric Structures with Diaphragm Flexibility

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Hamed Eivani ◽  
Abdolreza S. Moghadam ◽  
Armin Aziminejad ◽  
Masoud Nekooei
Keyword(s):  
Seismic Behavior ◽  
Time History ◽  
Asymmetric Structures ◽  
Optimum Configuration ◽  
Yield Level ◽  
Wide Range ◽  
Engineering Demand Parameter ◽  
Flexible Diaphragm ◽  
Torsionally Stiff ◽  
Dynamic Time

The seismic behavior of asymmetric structures with a flexible diaphragm was studied by conducting inelastic dynamic time-history analyses. Asymmetric structures with different configurations of mass, stiffness, and strength centers, in combination with a wide range of diaphragm flexibility, were evaluated. The behavior of structures was studied by considering three aspects:(1)effect of structural asymmetry on diaphragms deformation;(2)effect of diaphragm flexibility on demands of the lateral load-resisting elements;(3)optimum configuration of mass, stiffness, and strength centers to limit important engineering demand parameters in asymmetric structures with a flexible diaphragm. The results showed that the shear-dominant deformation of diaphragms is sensitive to both structure asymmetry specifications and the degree of diaphragm flexibility; therefore, it can be used for the qualitative classification of the seismic behavior of structures. Also, the center of strength in structures with flexible diaphragm is more important relative to the stiffness center and has a significant effect on engineering demands at all levels of diaphragm flexibility. Moreover, it was found that a suitable configuration of centers in torsionally stiff structures depends on the degree of diaphragm flexibility, in addition to the intensity of earthquakes (structure yield level) and selected engineering demand parameter.

Response Law and Influencing Factors of the Soil under Action of Pile Driving Vibration Based on Midas/GTS

2013 ◽  
Vol 353-356 ◽  
pp. 979-983
Author(s):  
Dong Zhang ◽  
Jing Bo Su ◽  
Hui De Zhao ◽  
Hai Yan Wang
Keyword(s):  
Damping Ratio ◽  
Large Diameter ◽  
Time History ◽  
Pile Driving ◽  
Analysis Model ◽  
Vibration Load ◽  
History Analysis ◽  
Study Results ◽  
Propagation Law ◽  
Dynamic Time

Due to the upgrade and reconstruct of a high-piled wharf, the piling construction may cause the damage of the large diameter underground pipe of a power plant nearby. For this problem, a dynamic time-history analysis model was established using MIDAS/GTS program. Based on the analysis of the pile driving vibration and its propagation law, some parameters, such as the modulus of the soil, the Poissons ratio of soil, the action time of vibration load and the damping ratio of the soil that may have an effect on the response law of the soil, were studied. The study results not only serve as an important inference to the construction of this case, but also accumulate experience and data for other similar engineering practices.

Seismic Vulnerability Analysis of FRP Retrofitting Industrial Buildings

2015 ◽  
Vol 724 ◽  
pp. 353-357
Author(s):  
Jian Zhu ◽  
Ping Tan ◽  
Pei Ju Chang
Keyword(s):  
Seismic Vulnerability ◽  
Response Spectrum ◽  
Time History ◽  
Seismic Intensity ◽  
Fiber Reinforced Polymers ◽  
Infill Wall ◽  
Intensity Index ◽  
Industrial Buildings ◽  
Dynamic Time ◽  
Masonry Infill Wall

This study focus on derivation of such vulnerability curves using Fiber Reinforced Polymers technologies retrofitted conventional RC industrial frames with masonry infill wall. A set of stochastic earthquake waves which compatible with the response spectrum of China seismic code are created. Dynamic time history analysis is used to compute the random sample of structures. Stochastic damage scatter diagrams based different seismic intensity index are obtained. Seismic vulnerability of FRP-reinforced RC industrial frames is lower than unreinforced frames obviously, and seismic capability of frames using FRP technologies is enhanced especially under major earthquake.

Seismic Behavior of Curved Bridge in Mountain Area

2019 ◽  
Author(s):  
Shuichi Fujikura ◽  
Yuji Sakakibara ◽  
Minh Hai Nguyen ◽  
Akinori Nakajima
Keyword(s):  
Seismic Behavior ◽  
Near Field ◽  
Time History ◽  
Longitudinal Direction ◽  
Mountain Area ◽  
Curved Bridge ◽  
Horizontally Curved ◽  
The 2016 Kumamoto Earthquake ◽  
Post Impact ◽  
Nonlinear Time History

<p>The 2016 Kumamoto Earthquake occurred in central Kyushu, Japan, on April 14th with Mw 6.2 followed by the Mw 7.0 mainshock on April 16th. These earthquakes were mainly caused by the Futagawa fault and Hinagu fault where surface ruptures extended about 34 km long. Some of the bridges located in mountain area and close to the fault were damaged due to these near‐field earthquakes. Oginosaka Bridge is one of them and is a horizontally curved bridge with longitudinal and transverse slope, which is a feature of the bridges located in mountain area. The superstructure was rotated on plan and displaced transversely at both abutments to the opposite side, and there was an evidence of the deck‐abutment pounding in longitudinal direction. In order to investigate the seismic behavior of the curved bridge, nonlinear time‐history analyses including a deck‐abutment pounding interaction were carried out. The deck‐abutment pounding interaction considered in the analyses could capture the post‐impact response of the superstructure. The near‐field ground motions were used for the analyses. The analytical results showed that the curved bridge is susceptible to the deck rotation caused by pounding in longitudinal direction at the deck end under earthquake loading.</p>

scholarly journals Seismic Performance Analysis of a Connected Multitower Structure with FPS and Viscous Damper

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaohan Wu ◽  
Jun Wang ◽  
Jiangyong Zhou
Keyword(s):  
Seismic Behavior ◽  
Passive Control ◽  
Time History ◽  
Tuned Mass Damper ◽  
Seismic Excitations ◽  
History Analysis ◽  
Mass Damper ◽  
Tower Structure ◽  
Design Requirements ◽  
Friction Pendulum

A high four-tower structure is interconnected with a long sky corridor bridge on the top floor. To reduce the earthquake responses and member forces of the towers and sky corridor bridge, a passive control strategy with a friction pendulum tuned mass damper (FPTMD) was adopted. The sky corridor bridge was as the mass of FPTMD. The connection between the towers and the sky corridor bridge was designed as flexible links, where friction pendulum bearings (FPBs) and viscous dampers were installed. Elastoplastic time-history analysis was conducted by using Perform-3D model to look into its seismic behavior under intensive seismic excitation. The optimal design of the FPTMD with varying friction coefficients and radius of friction pendulum bearing (FPB) under seismic excitations was carried out, and the seismic behavior of the structure was also investigated at the same time.Results show that, for this four-tower connected structure, the friction pendulum tuned mass damper (FPTMD) has very well effect on seismic reduction. The structure can meet the seismic resistance design requirements.

Settlement Analysis of Soft Ground Replacement under Earthquake

2012 ◽  
Vol 166-169 ◽  
pp. 2379-2382 ◽  
Author(s):  
Zhong Liu ◽  
Shu Hong An ◽  
Rong Hong Yuan ◽  
Fei Li
Keyword(s):  
Time History ◽  
Vertical Displacement ◽  
Response Analysis ◽  
Soft Ground ◽  
Positive Contribution ◽  
Foundation Soil ◽  
Time History Response ◽  
Dynamic Time ◽  
Settlement Analysis ◽  
Different Thickness

The dynamic time-history response analysis method was employed to analyze the dynamic response of soft ground replacement with sand-gravel cushion. The deformation distribution of soft ground replacement with different thickness sand-gravel cushion was investigated under seismic wave. The results reveal that the bearing and asti-deformation capacity can be improved effectively for replacement sand-gravel cushion under earthquake loads by increasing the thick of cushion. The vertical displacement of foundation soil decreases gradually with the increase of the thick of cushion. The practice shows that replacement sand-gravel cushion provides a positive contribution to the aseismic effect of foundation soils mass. The present research can provide some references to similar projects.

Thermal Response of a Viscoelastic Rod Under Cyclic Loading

1974 ◽  
Vol 41 (1) ◽  
pp. 229-233 ◽  
Author(s):  
S. Mukherjee
Keyword(s):  
Cyclic Loading ◽  
Thermal Response ◽  
Time History ◽  
Thermomechanical Coupling ◽  
Large Strains ◽  
Driving Frequency ◽  
Wide Range ◽  
History Of ◽  
Complex Young’S Modulus ◽  
Viscoelastic Rod

Thermal response of a viscoelastic rod under cyclic loading is discussed by determining the stresses and temperature in a viscoelastic rod insulated on its lateral surface and driven by a sinusoidal stress at one end. Temperature dependence of the complex Young’s modulus of the rod and the effect of thermomechanical coupling are included in the analysis. A method of finite differences is used to directly determine the steady-state stresses and temperature without obtaining the complete time history of the process. The iterative algorithm used is very efficient and converges rapidly for a wide range of driving stress amplitudes and frequencies. It is found that rapid rise of temperature to dangerous levels occurs for relatively low values of driving stress amplitudes, especially if the driving frequency is close to one of the critical frequencies of the rod. Drastic softening of the rod leads to large strains. Thus failure of the rod could occur at low values of the driving stress.

Time and Frequency Domain Investigation of the Static and Dynamic Characteristics of Micro-Drilling

Manufacturing ◽  
2003 ◽  
Author(s):  
Anping Guo ◽  
Steve Batzer ◽  
John Roth
Keyword(s):  
Tool Wear ◽  
Dynamic Characteristics ◽  
Time History ◽  
Drilling Process ◽  
Dynamic Features ◽  
Proper Order ◽  
Micro Drilling ◽  
On Line ◽  
Wear Monitoring ◽  
Dynamic Time

In this paper, the dynamic characteristics of micro-drilling process under different cutting conditions and the resulting correlation to tool wear have been studied. Two types of drills, three spindle speeds and two kinds of workpiece materials were used. In-process cutting forces and accelerations were measured. The signals were analyzed in both the time and frequency domains. Some interesting phenomena were observed in the dynamic time-history response during drilling. Progressive functions with the proper order were obtained to describe the curve of the average thrust force with the number of the holes drilled. Dynamic features which were sensitive to tool wear were found. The changing trends of these dynamic features as the drill wear progresses show a feasibility to develop an on-line drill wear monitoring system by evaluating the changes in dynamic features.

Dynamic Time-History Response of Cylindrical Tank Considering Fluid - Structure Interaction due to Earthquake

2014 ◽  
Vol 617 ◽  
pp. 66-69 ◽  
Author(s):  
Kamila Kotrasova ◽  
Ivan Grajciar ◽  
Eva Kormaníková
Keyword(s):  
Fluid Structure Interaction ◽  
Time History ◽  
Problem Analysis ◽  
Arbitrary Lagrangian Eulerian ◽  
Cylindrical Tank ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Ale Formulation ◽  
Time History Response ◽  
Dynamic Time

Ground-supported cylindrical tanks are used to store a variety of liquids. The fluid was develops a hydrodynamic pressures on walls and bottom of the tank during earthquake. This paper provides dynamic time-history response of concrete open top cylindrical liquid storage tank considering fluid-structure interaction due to earthquake. Numerical model of cylindrical tank was performed by application of the Finite Element Method (FEM) utilizing software ADINA. Arbitrary-Lagrangian-Eulerian (ALE) formulation was used for the problem analysis. Two way Fluid-Structure Interaction (FSI) techniques were used for the simulation of the interaction between the structure and the fluid at the common boundary

A Comparison of Self-Rectifying Turbines for OWC Based Wave Energy Power Extracting Device Using Numerical Simulation

2002 ◽  
Author(s):  
A. R. Ansari ◽  
H. B. Khaleeq ◽  
A. Thakker
Keyword(s):  
Numerical Simulation ◽  
Wave Energy ◽  
Sea Water ◽  
Time History ◽  
Flow Conditions ◽  
Wells Turbine ◽  
Impulse Turbine ◽  
Simulation Techniques ◽  
Simple Geometry ◽  
Wide Range

This paper presents a comparison of self-rectifying turbines for the Oscillating Water Column (OWC) based Wave Energy power extracting device using numerical simulation. The two most commonly used turbines for OWC based devices, the Impulse and the Wells turbines were evaluated under real sea simulated conditions. Assuming the quasi-steady condition, experimental data for both 0.6m turbines with 0.6 hub to tip ratio was used to predict their behavior under real sea conditions. The real sea water surface elevation time history data was used to simulate the flow conditions using standard numerical simulation techniques. A simple geometry of the OWC was considered for the simulation. The results show that the overall mean performance of an Impulse turbine is better than the Wells turbine under unsteady, irregular real sea conditions. The Impulse turbine was observed to be more stable over a wide range of flow conditions. This paper reports the comparison of performance characteristics of both these turbines under simulated real sea conditions.

Novel Hanger Design to Improve the Robustness of Through Arch Bridges

2011 ◽  
Vol 90-93 ◽  
pp. 862-868
Author(s):  
Qi Ming Wu ◽  
Dang Qi Yang ◽  
Fei Cui ◽  
Xiao Wei Yi ◽  
Rui Juan Jiang
Keyword(s):  
Progressive Collapse ◽  
Time History ◽  
Structural Members ◽  
New Approach ◽  
Arch Bridge ◽  
Structural Robustness ◽  
Arch Bridges ◽  
Dynamic Time ◽  
The Impact ◽  
Emergency Measures

Hangers in through arch bridges are important components since they suspend the bridge deck from the arch ribs. Local damage at a hanger may lead to progressive damage of various components in the arch bridge or even progressive collapse of the bridge. In this paper, the conventional design of double-hangers in through arch bridges is reviewed. Then a new approach to design the double-hangers is put forward. The suitability and robustness of this approach is then verified by a numerical simulation of a real through arch bridge. The impact effects induced by local hanger fracture on other structural members are simulated by dynamic time-history analyses. The new approach to design the hangers for through arch bridges is shown to improve the structural robustness. With the application of the new way put forward here, when one or more hangers are damaged to fail, the through arch bridge will not be endangered and will still maintain the overall load-bearing capacity during an appropriate length of time to allow necessary emergency measures to be taken, which illustrates the leading principle of structural robustness well.

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