scholarly journals A 3D Direct Vehicle-Pavement Coupling Dynamic Model and Its Application on Analysis of Asphalt Pavement Dynamic Response

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Peng Cao ◽  
Changjun Zhou ◽  
Decheng Feng ◽  
Youxuan Zhao ◽  
Baoshan Huang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Dynamic Model ◽  
Static Analysis ◽  
Moving Load ◽  
Dynamic Responses ◽  
Pavement Surface ◽  
Coupling Dynamic ◽  
Pavement Structure ◽  
Coupling Dynamic Model

Currently dynamic response of the pavement structure is widely studied in pavement engineering. A 3D direct vehicle-pavement coupling dynamic model was developed to describe the pavement dynamic responses in this paper. The moving vehicle was simplified as spring-dashpot components, and the pavement structure was simulated using three-dimension finite element model. Based on Newton iteration and central difference integration algorithm, the static and dynamic coupling reactions between the pavement structure and vehicle were considered using finite element platform ABAQUS. The numerical results fit analytic results very well in static analysis and fit experiment results in dynamic analysis well too. The simulated results indicate that the dynamic pavement surface deflection is much higher than the situation in static analysis, due to the overlapping effect. This phenomenon enhances when vehicle speed increases. A discontinuous zone of shear stress was observed on the base surface between the location under moving load and the location the moving load just passed. It was also found that the vertical fluctuation exists on the vehicle even if there is no roughness on the pavement surface. In general, the developed 3-D direct vehicle-pavement coupling dynamic model was validated to be effective on evaluating pavement dynamic responses.

scholarly journals Dynamic Responses of a Twin-Tunnel Subjected to Moving Loads in a Saturated Half-Space

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-lei Sun ◽  
An-hua Chen ◽  
Li Shi ◽  
Xue-yu Geng ◽  
Yu Wang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Saturated Porous Medium ◽  
Moving Load ◽  
Surrounding Medium ◽  
Element Model ◽  
Dynamic Responses ◽  
3D Finite Element ◽  
Twin Tunnel ◽  
Tunnel Model

With the fast development of rail transit, the environmental vibration problems caused by subways have received increasing attention. A 3D finite element model was built in this study to investigate the ground vibrations induced by the moving load operating in the parallel twin tunnels. Compared to the model consisting of a single tunnel that was commonly adopted in the past studies, a pair of tunnels is considered and the surrounding medium of the tunnels is taken as a saturated porous medium. The governing equations of the 3D finite element method modeling of the saturated poroelastic soil have been derived according to Biot’s theory. Computed results showed that the dynamic response of the twin-tunnel model is greater than that of the single tunnel model. And the spacing between two tunnels, tunnel buried depth, and load moving speed are the essential parameters to determine the dynamic response of the tunnel and soil.

Dynamic Response of Multi-bay Frames Subjected to Successive Moving Forces

2019 ◽  
Vol 19 (04) ◽  
pp. 1950042
Author(s):  
Salih Demirtas ◽  
Hasan Ozturk ◽  
Mustafa Sabuncu
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Moving Load ◽  
Single Point ◽  
Vertical Direction ◽  
Point Load ◽  
Dynamic Responses ◽  
Moving Loads ◽  
Element Analysis ◽  
Constant Interval

This paper investigates the dynamic responses of multi-bay frames with identical bay lengths subjected to a transverse single moving load and successive moving loads with a constant interval at a constant speed. The effects of the bay length and the speed of the moving load on the response of the multi-bay frame subjected to a single point load are investigated numerically by the finite element method. A computer code is developed by using MATLAB to perform the finite element analysis. The Newmark method is employed to solve for the dynamic responses of the multi-bay frame. With this, the dynamic response of the frame subjected to successive moving loads with a constant interval is investigated. Also, the resonance and cancellation speeds are determined by using the 3D relationship of speed parameter-force span length to beam length ratio-dynamic magnification factor and the associated contour lines. The maximum impact factor of a 1-bay frame and multi-bay frames under single moving load are determined at the specific speed parameters. Those values are independent of elastic modulus, area moment of inertia, beam/column lengths of the frame and also the number of bays forming the frame. It is also found that the first resonance response in the vertical direction of the frame is related to the second mode of vibration.

Research on Dynamic Response of Pavement under Moving Vehicle Loading Using Three Dimensional Finite Element Method

2013 ◽  
Vol 444-445 ◽  
pp. 1197-1203 ◽  
Author(s):  
You Xuan Zhao ◽  
Yan Jun Qiu ◽  
Peng Cao ◽  
Chang Fa Ai
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Static Analysis ◽  
Vertical Displacement ◽  
Numerical Results ◽  
Response Analysis ◽  
Integration Algorithm ◽  
Moving Vehicle ◽  
Vehicle Loading ◽  
Pavement Structure

To analyze the dynamic response of the pavement structure under moving vehicle loading is always a hot point in pavement engineering. In this paper, the moving vehicle has been simplified as spring-dashpot components and the pavement structure has also been discrete using three-dimension finite element model. Based on Newton iteration and central difference integration algorithm, the static and dynamic coupling reactions between pavement structure and vehicle have also been considered using finite element platform ABAQUS. The numerical results and analytic results can fit very well in static analysis, meanwhile the numerical results and experiment results can fit very well in dynamic analysis. Based on preceding verified numerical model, a few interesting phenomenon have been discovered. The pavement dynamic vertical displacement in upper layer is much higher than the situation in static analysis, because the vertical displacement is superimposed during the dynamic response analysis. Furthermore the vertical fluctuation of the vehicle's bar center exists even the vehicle moving in the initial even pavement, and the inertial forces is the most important reason to induce this behavior. In the last, this paper has proposed a more accurate, fast and concrete evidence to explain the reason that the dynamic response has obvious relationship with the diseases in pavement layer.

Dynamic Simulation Analysis of Shipborne Missile Launching under High-Wave-Level Environment

2012 ◽  
Vol 569 ◽  
pp. 380-385
Author(s):  
Zhou Zhong ◽  
Yi Jiang ◽  
Yong Yuan Li ◽  
Chong Zhang
Keyword(s):  
Dynamic Response ◽  
Dynamic Model ◽  
Dynamic Simulation ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Flexible Coupling ◽  
High Wave ◽  
Model And Simulation ◽  
Coupling Dynamic ◽  
Coupling Dynamic Model

In order to study the dynamic response of shipborne missile vertical launching under high-wave-level environment, the rigid-flexible coupling dynamic model of launching system was built by ways of virtual prototype technology. According to simulations for different launching conditions, missile attitude parameters were acquired, and interference of various parts was analyzed. The result shows that the dynamic model and simulation method proposed in this paper are effective and practicable.

scholarly journals Thermos-Solid-Gas Coupling Dynamic Model and Numerical Simulation of Coal Containing Gas

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiao Fukun ◽  
Meng Xin ◽  
Li Lianchong ◽  
Liu Jianfeng ◽  
Liu Gang ◽  
...  
Keyword(s):  
Principal Stress ◽  
Dynamic Model ◽  
Gas Flow ◽  
Flow Behavior ◽  
Coupling Model ◽  
Gas Pressure ◽  
Permeability Model ◽  
Gas Seepage ◽  
Coupling Dynamic ◽  
Coupling Dynamic Model

Based on gas seepage characteristics and the basic thermo-solid-gas coupling theory, the porosity model and the dynamic permeability model of coal body containing gas were derived. Based on the relationship between gas pressure, principal stress and temperature, and gas seepage, the thermo-solid-gas coupling dynamic model was established. Initial values and boundary conditions for the model were determined. Numerical simulations using this model were done to predict the gas flow behavior of a gassy coal sample. By using the thermo-solid-gas coupling model, the gas pressure, temperature, and principal stress influence, the change law of the pressure field, displacement field, stress field, temperature field, and permeability were numerically simulated. Research results show the following: (1) Gas pressure and displacement from the top to the end of the model gradually reduce, and stress from the top to the end gradually increases. The average permeability of the Y Z section of the model tends to decrease with the rise of the gas pressure, and the decrease amplitude slows down from the top of the model to the bottom. (2) When the principal stress and temperature are constant, the permeability decreases first and then flattens with the gas pressure. The permeability increases with the decrease of temperature while the gas pressure and principal stress remain unchanged.

scholarly journals A new vertical dynamic model for railway vehicle with passenger-train-track coupling vibration

2019 ◽  
Vol 234 (1) ◽  
pp. 134-146
Author(s):  
Yuewei Yu ◽  
Leilei Zhao ◽  
Changcheng Zhou
Keyword(s):  
Dynamic Model ◽  
Railway Vehicle ◽  
Train Track ◽  
Passenger Train ◽  
Railway Vehicles ◽  
Vertical Coupling ◽  
Track System ◽  
Coupling Dynamic ◽  
Train System ◽  
Coupling Dynamic Model

In order to further reveal the vertical random vibration characteristics of railway vehicles, using the system engineering method, taking the passenger, the train system, and the track system (ballast track) as a unified whole, a passenger-train-track vertical coupling dynamic model is established, and the vibration differential equations of the model are derived. In the model, passengers are regarded as a single-degree-of-freedom system attached to the bottom of the carriage, the train system is represented as a 10-degree-of-freedom multi-rigid body model, the track system is regarded as the infinite long Euler beam model with three layers of continuous elastic point support, and the Hertz nonlinear elastic contact theory is applied to the wheel and rail coupling relationship. Based on this, the time-domain numerical solution of the passenger-train-track vertical coupling dynamic model is given by using Newmark- β implicit integration algorithm, and the correctness of the model is verified by the real vehicle test. This study can provide some theoretical basis for the design of railway vehicles and provide fundamentals for the coordinated control and system optimization of railway vehicle ride comfort.

Effects of High-Speed Railway in Tunnel on Vibration Response of Upper Building

2013 ◽  
Vol 482 ◽  
pp. 155-162
Author(s):  
Si Hui Xu ◽  
Xiao Hui Zhang ◽  
Han Chen
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Reaction Force ◽  
Element Model ◽  
Vibration Response ◽  
Vibration Level ◽  
High Speed Railway ◽  
Proper Distance ◽  
Coupling Dynamic ◽  
Coupling Dynamic Model

In order to study the effects of high-speed railway in tunnel on vibration response of upper building, the Vehicle-Track-Tunnel-Soil-Building coupling dynamic model was established, and the reaction force of fasteners was used to transmit between Vehicle-Track coupling dynamic model and Tunnel-Soil-Building finite element model. According to modal analysis for typical section of building, sensitive frequency range and sensitive structure locations were obtained. In terms of two conditions, Tunnel-Building Integrated Structure and building are evaded from tunnel for some distance, 1/3 octave vibration level and VLZ vibration acceleration level for all measuring points were calculated to analyze the vibration response of building. The results are shown as follows: for Tunnel-Building Integrated Structure, the overall vibration level is high,which is above 65dB. 2-3dB will be reduced by decreasing speed and improving standard of track. when building is evaded from tunnel for some distance, with larger evaded distance, the vibration response is slighter. However, when evaded distance is above 30m, vibration may be amplified ,so its necessary to select proper distance. Vibration response of structure is most strong when 4 lines meet under building, so strict limitation on meeting condition of trains can effectively reduce vibration level.

Mechanism Analysis of Rutting at Urban Intersections Based on Numerical Simulation of Moving Loads

2010 ◽  
Vol 152-153 ◽  
pp. 1192-1198 ◽  
Author(s):  
Ze Jiao Dong ◽  
Zong Jie Sun ◽  
Xiang Bing Gong ◽  
Hao Liu
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Asphalt Pavement ◽  
Moving Load ◽  
Maximum Shear Stress ◽  
Uniform Motion ◽  
Dynamic Mode ◽  
Mechanism Analysis ◽  
Horizontal Shear ◽  
Pavement Structure

Frequent starting and braking of vehicles causes rutting of asphalt pavement at urban intersection. As a result, dynamic response of pavement subjected to these kinds of vehicle loadings can be used to analyze rutting mechanism. At first, vehicle loading at urban intersection was described by a vertical and horizontal combined moving pressure with variable speeds. Then, three-dimensional finite element model in transient dynamic mode is developed based on the practical pavement structure. And the moving load, boundary conditions and material parameters were briefly introduced. Finally, through the comparison of time histories and spatial distribution among accelerating, decelerating and uniform motion, mechanism of rutting of asphalt pavement at urban intersections was illustrated according to the finite element simulation. It shows that frequent starting and braking of vehicle at urban intersections, obviously change the stress distribution within pavement structure compared with uniform motion case. The distribution and amplitude of maximum shear stress and horizontal shear stress was observed during the passage of the loading, which will result in shear flow deformation. Pavement structure subjected to moving load exhibits an alternative characteristic which will accelerate the rutting damage of pavement.

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