scholarly journals The Study on Nonlinear Model of Pantograph-catenary Coupling system for Straddle-type Monorail

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 212-220
Author(s):  
Zixue DU ◽  
Zhen YANG ◽  
Zhouzhou XU ◽  
Junchao ZHOU* ◽  
Zhongwei HOU

Based on the Lagrange equation, the linear and nonlinear dynamic models of straddle monorail pantograph considering the lateral vibration of bogie are derived. On this basis, the lateral coupling dynamic model of pantograph-catenary is established. Newmark method is used to solve the pantograph-catenary coupling dynamic model. In order to evaluate the applicability of the two models,this paper analyzed the contact force response of two model with different speeds. The reasearch show that when the speed is below 40 km/h, the contact forces of nonlinear model and linear model can reflects the lateral excitation of the finger plate. When the speed exceeds 40 km/h, only the nonlinear model can reflect the lateral excitation of finger palte, the nonlinear pantograph-catenary coupling dynamics model is more suitable to the straddle-type monorail pantograph-catenary coupling research.

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiao Fukun ◽  
Meng Xin ◽  
Li Lianchong ◽  
Liu Jianfeng ◽  
Liu Gang ◽  
...  

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.


Author(s):  
Yuewei Yu ◽  
Leilei Zhao ◽  
Changcheng Zhou

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.


Author(s):  
Yue-Qing Yu ◽  
Qian Li ◽  
Qi-Ping Xu

An intensive study on the dynamic modeling and analysis of compliant mechanisms is presented in this paper based on the pseudo-rigid-body model. The pseudo-rigid-body dynamic model with single degree-of-freedom is proposed at first and the dynamic equation of the 1R pseudo-rigid-body dynamic model for a flexural beam is presented briefly. The pseudo-rigid-body dynamic models with multi-degrees-of-freedom are then derived in detail. The dynamic equations of the 2R pseudo-rigid-body dynamic model and 3R pseudo-rigid-body dynamic model for the flexural beams are obtained using Lagrange equation. Numerical investigations on the natural frequencies and dynamic responses of the three pseudo-rigid-body dynamic models are made. The effectiveness and superiority of the pseudo-rigid-body dynamic model has been shown by comparing with the finite element analysis method. An example of a compliant parallel-guiding mechanism is presented to investigate the dynamic behavior of the mechanism using the 2R pseudo-rigid-body dynamic model.


2013 ◽  
Vol 482 ◽  
pp. 155-162
Author(s):  
Si Hui Xu ◽  
Xiao Hui Zhang ◽  
Han Chen

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.


2012 ◽  
Vol 594-597 ◽  
pp. 446-451
Author(s):  
Deng Ke Wang ◽  
Jian Ping Wei ◽  
Heng Jie Qin ◽  
Le Wei

Considering the variation of the porosity and permeability of coal containing gas at differential deformation stages, a dynamic model for porosity and permeability is developed based on the previous researches. Furthermore, taking coal containing gas as a kind of isotropic elastoplastic material and taking into account the effect of gas adsorption, the stress and seepage equations are derived and, the solid gas coupling model for coal containing gas is constructed, which is appropriate to describe the skeleton deformability of coal containing gas and the compressibility of gas under the solid-gas interaction condition. In addition, the numerical simulation model is built by using the finite element method, and the numerical calculation solution of the model for a special loading case is given in term of the constraint conditions and corresponding parameters. The research results may have significance for further enriching and improving solid-gas coupling theories for coal containing gas.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Peng Cao ◽  
Changjun Zhou ◽  
Decheng Feng ◽  
Youxuan Zhao ◽  
Baoshan Huang

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.


2010 ◽  
Vol 26-28 ◽  
pp. 706-709
Author(s):  
Yan Liu ◽  
Mao Fa Jiang ◽  
Li Xian Xu

For describing and resolving the process of chromium ore smelting reduction preferably, the coupling dynamic model was established using metallurgical thermodynamics, dynamics and reaction engineering. The different influencing factors were investigated and discussed. The results of the model show that the mass transfer of Cr2O3 in the slag phase is rate-determining step. The initial hot metal should contain definite chrome metal and the yield of chromium in slag should be controlled properly at 1560°C so as to decrease refining time considerably and improve production efficiency for producing stainless steel crude melts in a converter. A reference and basis for the constitution of rational processing route in a practical converter steelmaking have been afforded.


Author(s):  
Kyuho Lee ◽  
Jintai Chung

Several dynamic models are proposed for the contact analysis of a tensioned beam with a moving oscillator. Depending on whether the strain and stress used to derive the equations of motion are nonlinear, four models are established to analyze the beam deflections and the contact force between the beam and moving oscillator. We find that the differences in the contact forces and deflections computed with the models become large as the beam tension and moving velocity decrease and the natural frequency ratio of the oscillator to the beam increases. The nonlinear model derived with nonlinear strain and stress is desirable for an accurate analysis.


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