Study on Seismic Response Characteristics of Double Cables Suspension Bridge

2011 ◽  
Vol 105-107 ◽  
pp. 408-411
Author(s):  
Nan Hong Ding ◽  
Li Xia Lin ◽  
Yong Jiu Qian ◽  
Lei Huang
Keyword(s):  
Seismic Response ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Suspension Bridge ◽  
Dynamic Responses ◽  
Independent Effect ◽  
Shape Coefficient ◽  
Response Characteristics ◽  
Coupled Equations

Damping in double Cables suspension bridge composed of steel reinforcement beams and reinforced concrete tower is non-classical, which leads to coupled equations of motion in main coordinate system. Based on the complex damping theory, the viscous damping ratio is solved, which can be used to describe energy dissipation characteristics of non-classical damping system approximately. Seismic response of double chains suspension bridge is analyzed through an example of double chains suspension bridge, considering the geometric nonlinearity and non-classical damping. And numerical calculation is presented for seismic response subjected to independent effect or combination effect of three orthogonal components of seismic wave. Single cable suspension bridge can be taken as a special case of double cable suspension bridge, after the main cable shape coefficient is introduced. The dynamic responses of double cable suspension bridge and single cable suspension bridge are compared to reveal the characteristics of Seismic Response of double cable suspension bridge. The study of the dynamic responses characteristics of double cable suspension bridge has a positive significance on structural form selection of such type bridge during designing, dynamic performance evaluation and reinforcement design has positive significance.

Vibration of Double Cable Suspension Bridge under Vehicle Load

2011 ◽  
Vol 50-51 ◽  
pp. 328-332
Author(s):  
Nan Hong Ding ◽  
Li Xia Lin ◽  
Wei Hua Liao
Keyword(s):  
Dynamic Performance ◽  
Suspension Bridge ◽  
Longitudinal Axis ◽  
Dynamic Responses ◽  
Coupling Vibration ◽  
Shape Coefficient ◽  
Main Cable ◽  
Vehicle Loading ◽  
Impact Coefficient ◽  
Mass Spring

A single moving mass-spring-damper model is adopted to simulate the vehicle model. The equation of vehicle-bridge coupling vibration is derived, using D'Alembert principle and the conditions of displacement compatibility. The dynamic responses of a double cable suspension bridge to the vehicle moving at different speeds are analyzed, considering the geometric nonlinearity and the bridge carriageway irregularity factor, under two types of vehicle loading conditions, namely moving along the center and the eccentric longitudinal axis. Then the influence of vehicle velocity and bridge carriageway irregularity on impact coefficient of double cable suspension bridge is discussed. Single cable suspension bridge can be taken as a special case of double cable suspension bridge, after the main cable shape coefficient is introduced. The dynamic responses of double cable suspension bridge and single cable suspension bridge are compared to reveal the character of vehicle vibration of double cable suspension bridge. The study of the dynamic responses character of double cable suspension bridge has a positive significance on structural form selection of such type bridge during designing, dynamic performance evaluation and vibration control.

Three-Dimensional Vibrations of a Suspension Bridge Under Stochastic Traffic Flows and Road Roughness

2016 ◽  
Vol 16 (07) ◽  
pp. 1550038 ◽  
Author(s):  
Xinfeng Yin ◽  
Yang Liu ◽  
Shihui Guo ◽  
W. Zhang ◽  
C. S. Cai
Keyword(s):  
Dynamic Performance ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Coupled System ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Traffic Flows ◽  
Longitudinal Vibrations ◽  
Coupled Equations ◽  
Road Roughness

When studying the vibration of a bridge–vehicle coupled system, most researchers mainly focus on the vertical vibration of bridges under moving vehicular loads, while the lateral and longitudinal vibrations of the bridges and the stochastic characteristics of the traffic flows are neglected. However, for long-span suspension bridges, neglecting the bridge’s three-dimensional (3D) vibrations under stochastic traffic flows can cause considerable inaccuracy in predicting the dynamic performance. This study is mainly focused on establishing a new methodology fully considering a suspension bridge’s vertical, lateral, and longitudinal vibrations induced by stochastic traffic flows under varied road roughness conditions. A new full-scale vehicle model with 18 degrees of freedom (DOFs) was developed to predict the longitudinal and lateral vibrations of the vehicle. An improved Cellular Automaton (CA) model considering the influence of the next-nearest vehicle was introduced. The bridge and vehicles in traffic flow coupled equations are established by combining the equations of motion of both the bridge and vehicles using the displacement relationship and interaction force relationship at the patch contacts. The numerical simulations show that the proposed method can rationally simulate the 3D vibrations of the suspension bridge under stochastic traffic flows.

scholarly journals SIMULATION OF MATHEMATICAL MODEL FOR MONORAIL SUSPENSION SYSTEM UNDER DIFFERENT TRACK CONDITIONS

2018 ◽  
Vol 79 (2) ◽  
pp. 15-31
Author(s):  
Wafi A. Mabrouk ◽  
M. F. L. Abdullah
Keyword(s):  
Mathematical Model ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Research Work ◽  
Suspension System ◽  
Dynamic Responses ◽  
Central Difference ◽  
Central Difference Method ◽  
Model Features

Designing a new monorail suspension system for an existing monorail bogie to accommodate larger cars, locomotives and more passengers is a difficult and complicated problem to solve. This paper introduces a simulation of a mathematical model for a monorail suspension system that can be used as an analytical tool to investigate and predict the behavior of the model under different speeds and track conditions. In this paper, the simulation is performed to predict some dynamic characteristics monorail suspension system. This research work concentrates on the simulation of 15 degrees of freedom full-car Monorail suspension system. The model features the Monorail body, Front bogie, and rear bogie geometries, adopted equations of motion of the monorail suspension system and system matrices. Numerical Central Difference method was used to obtain the system responses subject to sinusoidal Track excitations. Three Track scenarios that have different loads and different driving speeds were conducted to investigate the monorail suspension system. The system results are analysed in terms of their dynamic responses. Fourier Fast transforms was used to calculate the frequency ranges of dynamic responses. As a result, some very important characteristics of the Monorail suspension system were revealed, with indicators that help to understand the effects of driving speeds and different loads, which can be used to better understand the system dynamic performance, to improve Monorail suspension system designs flaws detection.

Structural Simplification of Jack-Up Rig and Its Dynamic Responses in Regular Waves

1988 ◽  
Vol 32 (02) ◽  
pp. 134-153
Author(s):  
Jong-Shyong Wu ◽  
Cuann-Yeu Chang
Keyword(s):  
Virtual Work ◽  
Damping Ratio ◽  
Equations Of Motion ◽  
Dynamic Responses ◽  
Jacobi Method ◽  
Mode Shapes ◽  
Regular Waves ◽  
Static Condensation ◽  
Rigid Joints ◽  
Jack Up

This paper is composed of two main parts: simplification of leg structure of the jack-up rig, and dynamic analysis of the entire rig due to excitation of regular waves. First, the legs of spatial beamlike lattice with rigid joints are replaced by the equivalent beams through application of the theory of static condensation and the principle of virtual work. Then the equations of motion of the entire rig are derived based on the simplified mathematical model, and the natural frequencies and mode shapes are sought by the Jacobi method. Finally, the dynamic behavior of the hinged rig and fixed rig operating in four kinds of water depths (and hence effective leg lengths) and wave heights is studied by means of the mode superposition technique. The phase angles between responses of the legs and the influence on responses of support conditions at the seabed, wave attack angle, and damping ratio are the key points of the investigation.

scholarly journals Analysis of a Benchmark Building Installed with Tuned Mass Dampers under Wind and Earthquake Loads

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
S. Elias ◽  
R. Rupakhety ◽  
S. Olafsson
Keyword(s):  
Equations Of Motion ◽  
Equal Mass ◽  
Dynamic Responses ◽  
Acceleration Response ◽  
Tuned Mass Dampers ◽  
Response Control ◽  
Earthquake Loads ◽  
Coupled Equations ◽  
Wind Response ◽  
The One

This study presents analysis of a benchmark building installed with tuned mass dampers (TMDs) while subjected to wind and earthquake loads. Different TMD schemes are applied to reduce dynamic responses of the building under wind and earthquakes. The coupled equations of motion are formulated and solved using numerical methods. The uncontrolled building (NC) and the controlled building are subjected to a set of 100 earthquake ground motions and wind forces. The effectiveness of using different multiple TMD (MTMD) schemes as opposed to single TMD (STMD) is presented. Optimal TMD parameters and their location are investigated. For a tall structure like the one studied here, TMDs are found to be more effective in controlling acceleration response than displacement, when subjected to wind forces. It is observed that MTMDs with equal stiffness in each of the TMDs (usually considered for wind response control), when optimized for a given structure, are effective in controlling acceleration response under both wind and earthquake forces. However, if the device is designed with equal mass in every floor, it is less effective in controlling wind-induced floor acceleration. Therefore, when it comes to multihazard response control, distributed TMDs with equal stiffnesses should be preferred over those with equal masses.

scholarly journals Computation of Rayleigh Damping Coefficients for the Seismic Analysis of a Hydro-Powerhouse

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhiqiang Song ◽  
Chenhui Su
Keyword(s):  
Seismic Response ◽  
Seismic Analysis ◽  
Damping Ratio ◽  
Least Square Method ◽  
Least Square ◽  
Dynamic Responses ◽  
Damping Coefficients ◽  
Rayleigh Damping ◽  
Damping Matrix ◽  
Fundamental Frequencies

The mass and stiffness of the upper and lower structures of a powerhouse are different. As such, the first two vibration modes mostly indicate the dynamic characteristics of the upper structure, and the precise seismic response of a powerhouse is difficult to obtain on the basis of Rayleigh damping coefficients acquired using the fundamental frequencies of this structure. The damping ratio of each mode is relatively accurate when the least square method is used, but the accuracy of the damping ratios that contribute substantially to seismic responses is hardly ensured. The error of dynamic responses may even be amplified. In this study, modes that greatly influence these responses are found on the basis of mode participation mass, and Rayleigh damping coefficients are obtained. Seismic response distortion attributed to large differences in Rayleigh damping coefficients because of improper modal selection is avoided by using the proposed method, which is also simpler and more accurate than the least square method. Numerical experiments show that the damping matrix determined by using the Rayleigh damping coefficients identified by our method is closer to the actual value and the seismic response of the powerhouse is more reasonable than that revealed through the least square method.

scholarly journals Vibration Suppression of Wind/Traffic/Bridge Coupled System Using Multiple Pounding Tuned Mass Dampers (MPTMD)

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1133 ◽  
Author(s):  
Xinfeng Yin ◽  
Gangbing Song ◽  
Yang Liu
Keyword(s):  
Vibration Suppression ◽  
Equations Of Motion ◽  
Coupled System ◽  
Highway Bridges ◽  
Dynamic Responses ◽  
Viscoelastic Layer ◽  
Parameter Study ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Coupled Equations

Dynamic responses of highway bridges induced by wind and stochastic traffic loads usually exceed anticipated values, and tuned mass dampers (TMDs) have been extensively applied to suppress dynamic responses of bridge structures. In this study, a new type of TMD system named pounding tuned mass damper (PTMD) was designed with a combination of a tuned mass and a viscoelastic layer covered delimiter for impact energy dissipation. Comprehensive numerical simulations of the wind/traffic/bridge coupled system with multiple PTMDs (MPTMDs) were performed. The coupled equations were established by combining the equations of motion of both the bridge and vehicles in traffic. For the purpose of comparing the suppressing effectiveness, the parameter study of the different numbers and locations, mass ratio, and pounding stiffness of MPTMDs were studied. The simulations showed that the number of MPTMDs and mass ratio are both significant in suppressing the wind/traffic/bridge coupled vibration; however, the pounding stiffness is not sensitive in suppressing the bridge vibration.

Seismic response characteristics of multi-story subway station through shaking table test

2021 ◽  
pp. 136943322199329
Author(s):  
Zhiyi Chen ◽  
Pengfei Huang ◽  
Wei Chen
Keyword(s):  
Seismic Response ◽  
Shaking Table Test ◽  
Earth Pressure ◽  
Frequency Component ◽  
Shaking Table ◽  
Dynamic Responses ◽  
High Frequency Component ◽  
Subway Station ◽  
Response Characteristics ◽  
Dynamic Earth Pressure

A series of shaking table tests were carried out to investigate the seismic response characteristics of a multi-story subway station. Dynamic responses, including accelerations of the soils and the underground structure, layer drift, dynamic earth pressure, and lateral deformation of soils were recorded and analyzed. Several seismic characteristics of multi-story subway station structures are figured out. It is found that in addition to the racking deformation, the rotation vibration is observed for the multi-story subway station subjected to acceleration waves. From the viewpoint of frequency, the low-frequency component and high-frequency component of the acceleration response of the subway station represent the translation and rotation component of the multi-story subway structure, respectively. In addition, the rotation vibration of the deep-depth structure leads to the local squeezing and detachment from the surrounding soils alternately at both top and bottom ends of the sidewalls. This results in the hump-shaped distribution of dynamic earth pressure. The racking deformation of the multi-story subway station has a linear relationship with the dynamic earth pressure at a certain area along the sidewall, where the top of hump-shaped distribution of dynamic earth pressure is.

Seismic Response Evaluation of Buildings Considering Soil Flexibility

2011 ◽  
Vol 243-249 ◽  
pp. 1383-1390 ◽  
Author(s):  
Magdy S. El-Azab ◽  
Sayed Mahmoud ◽  
Ayman Abd-Elhameed
Keyword(s):  
Seismic Response ◽  
Shear Wave ◽  
Equations Of Motion ◽  
Computational Simulation ◽  
Time History ◽  
Velocity Variation ◽  
Peak Response ◽  
Coupled Equations ◽  
Soil Flexibility ◽  
Response Amplification

This research attempts to investigate the effect of soil-structure interaction (SSI) on the seismic response of buildings. Computational simulation of a one storey building having different natural periods is performed using time history analysis. Different earthquake motions with different peak ground accelerations (PGA) levels are used as excitations. The ground motion records have been selected in order to ensure low, moderate, and high PGA levels. Moreover, sandy soil with several values of shear wave velocities is used in order to investigate the sensitivity of the seismic response to the velocity variation. An efficient discrete-element model which represents the rotational and horizontal degrees of freedom of the soil mass is considered in the analysis. The coupled equations of motion for the building model with SSI are presented and solved in incremental form using the Newmark's step by step iteration method. In general, the results of the study in terms of response, peak response and peak response amplification show significant changes in considering and ignoring SSI effect. In particular, the numbers of significant cycles of large response amplitude for the building have been increased due to the inclusion of SSI. Moreover, considering the soil flexibility amplifies the peak response of buildings with low natural periods. Furthermore, it has been found that, shear wave velocity variation shows appreciable changes in the peak dynamic response amplification and seems to be insignificant at high natural periods for all levels of earthquake excitations considered.

Seismic Response Analysis of Double Chains Suspension Bridge Considering Non-Classical Damping

2011 ◽  
Vol 255-260 ◽  
pp. 826-830 ◽  
Author(s):  
Nan Hong Ding ◽  
Li Xia Lin ◽  
Jia De Chen
Keyword(s):  
Seismic Response ◽  
Seismic Analysis ◽  
Damping Ratio ◽  
Suspension Bridge ◽  
Response Analysis ◽  
Equivalent Viscous Damping ◽  
Damping Theory ◽  
Damping Model ◽  
Equivalent Viscous Damping Ratio ◽  
Complex Damping

Damping in double chains suspension bridge is non-uniform, which leads to coupled motion equations in main coordinate system. Based on the complex damping theory to solve equivalent viscous damping ratio used to describe energy dissipation characteristics of non-classical damping system approximately, a method is proposed to analyze seismic response of double chains suspension bridge considering non-classical damping modified by measured value. Influence of different damping forms on seismic response of double chains suspension bridge is analyzed, considering classical damping and non-classical damping respectively, through an example of double chains suspension bridge. The analysis shows that non-classical damping has significant effect on seismic response, and response based on the classical damping model is not reliable to double chains suspension bridge. Non-classical damping model should be used in seismic analysis of double chains suspension bridge, however, the seismic response of non-classical damping system under the longitudinal or vertical seismic wave can be substituted approximately by the seismic response calculated according to damping ratio of concrete tower and steel stiffening girder respectively, which can simplify the calculation during preliminary analysis.

Sign in / Sign up

Export Citation Format

Share Document