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.

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.

Resistive Ballooning Modes in Three-Dimensional Configurations

1982 ◽  
Vol 37 (8) ◽  
pp. 848-858 ◽  
Author(s):  
D. Correa-Restrepo
Keyword(s):  
Growth Rates ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Coupled System ◽  
Small Constant ◽  
Ballooning Mode ◽  
The Stability ◽  
The Magnetic Field ◽  
Symmetric Systems ◽  
The Ideal

Resistive ballooning modes in general three-dimensional configurations are studied on the basis of the equations of motion of resistive MHD. Assuming small, constant resistivity and perturbations localized transversally to the magnetic field, a stability criterion is derived in the form of a coupled system of two second-order differential equations. This criterion contains several limiting cases, in particular the ideal ballooning mode criterion and criteria for the stability of symmetric systems. Assuming small growth rates, analytical results are derived by multiple-length-scale expansion techniques. Instabilities are found, their growth rates scaling as fractional powers of the resistivity

Dynamic Behavior of Damaged Bridge with Multi-Cracks Under Moving Vehicular Loads

2017 ◽  
Vol 17 (02) ◽  
pp. 1750019 ◽  
Author(s):  
Xinfeng Yin ◽  
Yang Liu ◽  
Lu Deng ◽  
Xuan Kong
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Coupled System ◽  
Interaction Force ◽  
Vehicle Model ◽  
Coupled Equations ◽  
Contact Points ◽  
Local Flexibility ◽  
Bridge Structures ◽  
Road Surface Roughness

When studying the vibration of a bridge–vehicle coupled system, most researchers mainly focus on the intact or original bridge structures. Nonetheless, a large number of bridges were built long ago, and most of them have suffered serious deterioration or damage due to the increasing traffic loads, environmental effect, material aging, and inadequate maintenance. Therefore, the effect of damage of bridges, such as cracks, on the vibration of vehicle–bridge coupled system should be studied. The objective of this study is to develop a new method for considering the effect of cracks and road surface roughness on the bridge response. Two vehicle models were introduced: a single-degree-of-freedom (SDOF) vehicle model and a full-scale vehicle model with seven degrees of freedom (DOFs). Three typical bridges were investigated herein, namely, a single-span uniform beam, a three-span stepped beam, and a non-uniform three-span continuous bridge. The massless rotational spring was adopted to describe the local flexibility induced by a crack on the bridge. The coupled equations for the bridge and vehicle were established by combining the equations of motion for both the bridge and vehicles using the displacement relationship and interaction force relationship at the contact points. The numerical results show that the proposed method can rationally simulate the vibrations of the bridge with cracks under moving vehicular loads.

Loading Test Scheme Research on Long-Span Suspension Bridges

2013 ◽  
Vol 785-786 ◽  
pp. 1248-1252
Author(s):  
Xiao Bin Li ◽  
Meng Yan ◽  
Qu Yu ◽  
Xiang Lin Zeng
Keyword(s):  
Field Test ◽  
Dynamic Performance ◽  
Suspension Bridge ◽  
Load Test ◽  
Suspension Bridges ◽  
Test Scheme ◽  
Loading Test ◽  
Linear Effect ◽  
Long Span ◽  
Capacity Loading

In order to get a full understanding the whole bridge's actual stress state and dynamic performance as well as to check whether the bridge structure could meet the requirements of carrying capacity and traffic capacity, loading test has been carried out to the Nanxi Yangtze River Bridge. As the bridge is a long-span suspension bridge, there is a significant geometric non-linear effect which must be considered in the calculation. Besides, a reasonable field test organization scheme is necessary to guarantee the success of the test since there are a variety of working conditions and a large number of loading trucks. Finally, this kind of static and dynamic load test has a high guiding significance to the field test.

Dynamic Performance of Vehicle–Guideway Bridge Systems for Low–Medium-Speed Maglev Trains Under Earthquakes

2021 ◽  
pp. 2150166
Author(s):  
Fenghua Huang ◽  
Bin Cheng ◽  
Nianguan Teng
Keyword(s):  
Seismic Analysis ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Coupled System ◽  
Seismic Effect ◽  
Vehicle Speed ◽  
Seismic Responses ◽  
Medium Speed ◽  
Direct Solution Method ◽  
Absolute Coordinate System

This paper developed a numerical model for predicting the seismic responses of vehicle–guideway bridge systems for low–medium-speed (LMS) maglev trains. Each vehicle was characterized as a multi-rigid-body with 50 degree of freedoms (DOFs), and the guideway bridge was modeled by the finite element method. The actively controlled electromagnetic forces were considered in simulating the vehicle–guideway interaction relationship. Subsequently, the equations of motion for the vehicle–guideway coupled system under earthquake were, respectively, established in relative and absolute coordinate systems to quantify the effect of structural pseudo-static components, so that the seismic effect can be taken into account. Case study was then conducted to thoroughly discuss the seismic responses of the vehicle–guideway coupled system in both time and frequency domains. Furthermore, parametric study was carried out to determine the effect of key parameters (i.e. vehicle speed, stiffness of guideway) on the system’s responses. The results show that the conventional seismic analysis method relative motion method (RMM) (ignoring the structural pseudo-static component) will considerably underestimate the seismic responses of the coupled system, especially of the vehicle. It is suggested that the formulation be established in the absolute coordinate system (i.e. using direct solution method, DSM) for more actual prediction. The frequency responses indicate that the vibrations of vehicle–guideway coupled system under earthquake relate significantly to the natural frequencies of vehicle and bridge, while the same is not true for the vehicle-induced excitation.

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.

Dynamic Characteristics Simulation and Analysis for the Stable Type Suspension Bridge

2013 ◽  
Vol 444-445 ◽  
pp. 173-177
Author(s):  
Xiao Chun Wang ◽  
Ben Ning Qu ◽  
Jiao Long Peng ◽  
Meng Xi Geng
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Suspension Bridge ◽  
Element Model ◽  
Fish Bone ◽  
Suspension Bridges ◽  
Stable Type ◽  
Stable Suspension ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Under the background of a stable type suspension bridge (A suspension bridge with a inverse-tensional system), the effect of inverse-tensional system for suspension bridge is studied. Using finite element method, three-dimensional finite element model of stable type suspension bridge and a common suspension bridge is established by fish bone model consisting of beam elements respectively. The finite element characteristic equation of two bridges is solved with Block Lanczos method respectively. 20 order eigenpairs of two kind of suspension bridges are obtained. The inherent characteristics of the two type bridges are analyzed comparatively. The results showed that due to the effect of inverse-tensional structures, the overall stiffness of the stable suspension bridge is better than common suspension bridge obviously, which can effectively suppress the torsional vibration of the suspension bridge.

scholarly journals Study on Seismic Control of Power Transmission Tower-Line Coupled System under Multicomponent Excitations

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Li Tian ◽  
Qiqi Yu ◽  
Ruisheng Ma
Keyword(s):  
Power Transmission ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Coupled System ◽  
Time Domain Analysis ◽  
Tuned Mass Damper ◽  
Transmission Tower ◽  
Line System ◽  
Seismic Control ◽  
Mass Damper

The seismic control of power transmission tower-line coupled system subjected to multicomponent excitations is studied in this paper. The schematic of tuned mass damper is introduced, and equations of motion of a system with tuned mass damper under multi-component excitations are proposed. Three-dimensional finite tower-line system models are created based on practical engineering in studying the response of this system without and with control. The time domain analysis takes into account geometric nonlinearity due to finite deformation. The optimal design of the transmission tower-line system with tuned mass damper is obtained according to different mass ratio. The effects of wave travel, coherency loss, and different site conditions on the system without and with control are investigated, respectively.

Elastic Waves in Generalized Thermo-Piezoelectric Transversely Isotropic Circular Bar Immersed in Fluid

2015 ◽  
Vol 8 (1) ◽  
pp. 82-103
Author(s):  
Palaniyandi Ponnusamy
Keyword(s):  
Classical Theory ◽  
Cross Sections ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Coupled System ◽  
Theory Of Elasticity ◽  
Inviscid Fluid ◽  
Displacement Potential ◽  
Modes Of Vibration

AbstractIn this paper, a mathematical model is developed to study the wave propagation in an infinite, homogeneous, transversely isotropic thermo-piezoelectric solid bar of circular cross-sections immersed in inviscid fluid. The present study is based on the use of the three-dimensional theory of elasticity. Three displacement potential functions are introduced to uncouple the equations of motion and the heat and electric conductions. The frequency equations are obtained for longitudinal and flexural modes of vibration and are studied based on Lord-Shulman, Green-Lindsay and Classical theory theories of thermo elasticity. The frequency equations of the coupled system consisting of cylinder and fluid are developed under the assumption of perfect-slip boundary conditions at the fluid-solid interfaces, which are obtained for longitudinal and flexural modes of vibration and are studied numerically for PZT-4 material bar immersed in fluid. The computed non-dimensional frequencies are compared with Lord-Shulman, Green-Lindsay and Classical theory theories of thermo elasticity for longitudinal and flexural modes of vibrations. The dispersion curves are drawn for longitudinal and flexural modes of vibrations. Moreover, the dispersion of specific loss and damping factors are also analyzed for longitudinal and flexural modes of vibrations.

Experimental and Numerical Studies of a Damaged Bridge Considering Stochastic Traffic Flows and Road Roughness

2017 ◽  
Vol 17 (08) ◽  
pp. 1750089 ◽  
Author(s):  
Xinfeng Yin ◽  
Yang Liu ◽  
Bo Kong ◽  
Suren Chen
Keyword(s):  
Surface Roughness ◽  
Traffic Flow ◽  
Three Dimensional ◽  
Interaction Force ◽  
Concrete Bridge ◽  
Traffic Flows ◽  
Vehicle Model ◽  
Coupled Equations ◽  
Numerical Studies ◽  
Damaged Zone

Experimental and numerical studies are performed to analyze a concrete bridge under moving vehicular loads considering the effects of the damage cracks, stochastic traffic flows, and bridge surface roughness. Specifically, (1) the crack zone in the concrete bridge is modeled by a damage function with three parameters, i.e. the length of damaged zone, the magnitude of the damage, and the variation of Young’s modulus of the material; (2) a cellular automation (CA) based traffic flow model is adopted, which can capture the basic features of the probabilistic traffic flows using realistic traffic rules; (3) a three-dimensional (3D) vehicle model and a single vehicle model are each used to simulate the vehicles in the traffic flow for computational efficiency; and (4) the bridge and vehicle coupled equations are established by combining those for the bridge and vehicles using the displacement and interaction force relationship at the contact patches. The experimental and numerical investigations are conducted to validate the proposed modeling methodology. As an illustration, a prototype concrete bridge structure with partial damage is studied. Finally, parametric studies are conducted to study the effects of damage cracks, stochastic traffic flows, and surface roughness on the dynamic displacement, impact factor, impact force, and dynamic load coefficient of the bridge.

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