Influence of Moving Vehicles on Vertical Vibration of Simply Supported Bridge

2013 ◽  
Vol 405-408 ◽  
pp. 1578-1586
Author(s):  
Yan Han ◽  
Xiao Dong Wang ◽  
Chao Qun Li

Euler beam dynamic analysis model under moving loads and wheels plus spring-damper-sprung mass action were established respectively. The simply-supported beam motion control equations were derived and the corresponding simulation analysis procedures were worked out. The vertical dynamic responses of simply-supported bridge under typical vehicles at different speeds were studied systematically. Impact factors calculated from the two analysis model were compared with the values of the current bridge specifications. It is shown that vehicle inertia force has little effect on the vertical deflection and vertical vibration acceleration of the bridge, the vehicle impact effect on bridge gradually go up with the passing speed increasing, vehicle weight has great influence on the vertical vibration of the bridge. The problem of passing overloaded vehicles must be considered seriously in bridge design and use.

2007 ◽  
Vol 345-346 ◽  
pp. 845-848
Author(s):  
Joo Yong Cho ◽  
Han Suk Go ◽  
Usik Lee

In this paper, a fast Fourier transforms (FFT)-based spectral analysis method (SAM) is proposed for the dynamic analysis of spectral element models subjected to the non-zero initial conditions. To evaluate the proposed SAM, the spectral element model for the simply supported Bernoulli-Euler beam is considered as an example problem. The accuracy of the proposed SAM is evaluated by comparing the dynamic responses obtained by SAM with the exact analytical solutions.


2014 ◽  
Vol 1065-1069 ◽  
pp. 962-968
Author(s):  
Yan Han ◽  
Xiao Dong Wang

To explore the practical rail-bridge seismic design methods, dynamic response analysis model of the train-rail-bridge system under seismic loads was established, and the widely used simply supported track-bridge in rail transport was taken for the study. By inputting different intensity and frequency artificial seismic waves to the train-rail-bridge system, the whole history of the vehicles running through the bridge is simulated and the dynamic responses of the bridge and the vehicles are calculated. The influence of train type, seismic intensity and spectral characteristics of the earthquake were analyzed. Taking Japanese traffic safety evaluation indexes including derailment coefficient, wheel offload rate and lateral wheel-rail force as evaluation criteria, the allowed lateral bridge displacement limits and acceleration limits that ensuring train running safety under earthquake were obtained, and the bridge vibration limit curve was drawn. Using Lagrange interpolation method, the mathematical expression of the curve was worked out, which can provide a reference to rail-bridge aseismic design.


2014 ◽  
Vol 919-921 ◽  
pp. 1164-1168
Author(s):  
Yu Yang ◽  
Yan Wang ◽  
Yun Fang Yang

Vertical vibration of identical simply supported bridges traversed by a train with uniformly distributed mass is investigated in this paper. The train with passengers onboard is simplified as a uniformly distributed two-layer spring-mass system as well as the bridges are simplified as consecutive simply supported Euler-Bernoulli beams. To analyze dynamic responses of the train and the bridges, the dynamic governing equation of the system is obtained and solved by a specific linear interpolating method and numerical integral methods. The result graphs indicate that dynamic responses of both beam and train carriage increase along with the mass ratio of bogie to car.


2015 ◽  
Vol 75 (11) ◽  
Author(s):  
Roslina Mohammad ◽  
Astuty Amrin ◽  
Sallehuddin Muhamad

The primary aim of this study had been to investigate the effects of water-filled flow on the transient response of a simply supported pipe subjected to dynamically applied loading. The importance of this study is manifested in numerous applications, such as oil and gas transportations, where dynamic loading can be the result of an accident. The classical Bernoulli-Euler beam theory was adopted to describe the dynamic behavior of an elastic pipe and a new governing equation of a long pipe transporting gas or liquid was derived. This governing equation incorporated the effects of inertia, centrifugal, and Coriolis forces due to the flowing water. This equation can be normalized to demonstrate that only two non-dimensional parameters governed the static and the dynamic responses of the system incorporating a pipe and flowing water. The transient response of this system was investigated based on a standard perturbation approach. Moreover, it had been demonstrated that the previous dynamic models, which largely ignored the internal flow effects and interactions between the flow and the structure, normally produced a large error and are inapplicable to the analysis of many practical situations. One interesting effect identified was that at certain flow ratio, the system became dynamically unstable and any, even very small, external perturbation led to a growing unstable dynamic behavior. Such behavior, which is called pipe whip, is well-known to everyone who waters a garden using a flexible long hose.


2012 ◽  
Vol 430-432 ◽  
pp. 1320-1325
Author(s):  
Jian Qing Bu ◽  
Hai Yun Wang

A new method is proposed to identify the bridge effective pre-stress from the dynamic responses induced by the vehicle moving on a simply-supported beam bridge with eccentric straight pre-stress, based on the sensitivity analysis. The bridge is modeled as Euler beam elements and the moving vehicle is modeled as a two-degree freedom system with five parameters. After calculating dynamic responses of the bridge by vehicle-bridge coupled vibration analysis, the dynamic responses sensitivity can be obtained by using the direct derivation method, and the regularization method is adopted to identify the effective pre-stress. The effects on the identified results from different responses, different measuring locations and different road surface roughness are considered in the numerical simulations. The simulation studies indicate that the proposed method can be used to identify the effective pre-stress accurately and effectively for a simply-supported PRC beam bridges.


2013 ◽  
Vol 405-408 ◽  
pp. 1852-1856
Author(s):  
Huai Liang Zhu ◽  
Xue Wang ◽  
Li Feng Yu

A dynamic model of vehicle-bridge interaction is presented considering the railway vehicle moving through bridge with varying velocity. Assuming the vehicle has a constant acceleration, the motion equations of coupled vehicle-bridge system were deduced based on DAlemberts principle and theory of Euler beam. Dynamic responses of system were analyzed both cases of the acceleration and drag acceleration for a moving car. Results show that the amplitudes of vibration of the system will enlarge sharply with the acceleration of vehicle increasing, and the maximum of responses occur when the vehicle moving at the middle point of bridge. In addition, the stiffness coefficient is one of the key factors to affect on dynamic responses of system. Generally, the suitable rigidity of structure is much important to decrease the responses and suppress the vibration of system.


2012 ◽  
Vol 178-181 ◽  
pp. 2424-2428
Author(s):  
Chun Sheng Shan ◽  
Wei Ye ◽  
Heng Li ◽  
Xiao Zhen Li

A novel simplified vehicle model i.e. arbitrary moving mass-spring systems model, which can be simplified into moving loads model, is put forward and proved to be capable of analyzing the vertical dynamic responses of bernoulli-euler beam. Based on the matlab platform, a simply supported beam with a span of 40 m serviced in Beijing-Shanghai High-speed Railway is selected as the case study. The similarities and differences of vertical dynamic responses of the bridge based on this two vehicle models are compared. On this basis, the effects of vehicle speed and bridge damping ratio on the bridge’s dynamic magnification factor is studied. The computation results show that this new vehicle model is effective and reliable in its practical application.


Author(s):  
P Lou ◽  
G-L Dai ◽  
Q-Y Zeng

Modal coordinate formulation for analysing the dynamic interaction between a moving train and a simply supported bridge is presented in this article. The train is composed of a series of identical vehicles, and each vehicle is modelled as a four-wheelset mass-spring-damper multi-rigid body system with two-stage suspension having ten degrees of freedom (DOFs). A simply supported bridge, together with the track, is modelled as a Bernoulli-Euler beam. The deflection of the beam is described by superimposing modes. The train and the beam are regarded as an entire dynamic system, and then the modal coordinate formulation with time-dependent coefficients for this system is directly derived from the principle of virtual work. The formulation is solved by direct time integration method, to obtain the dynamic responses of this system. The correctness of the proposed formulations is illustrated by a comparison with the existing literature. The formulation helps save computer time using a few beam modes for analysing the dynamic responses of an entire train-bridge interaction system. The proposed formulation can also be applied to analyse the dynamic responses of a simply supported bridge subjected to a moving train modelled as two-wheelset four DOFs vehicles. Two numerical examples are given for illustrating the applications of the proposed formulation.


2012 ◽  
Vol 594-597 ◽  
pp. 1552-1556
Author(s):  
Wei Ye ◽  
Xiao Zhen Li ◽  
Hong Duan ◽  
Chun Sheng Shan ◽  
Xiao Han Liu

In this thesis, the dynamic responses of simply supported beam bridge in a double-line railway under bidirectional moving loads are mainly studied. To study the characteristics of Euler- Bernoulli beam, a train is simplified as a series of concentrated forces with fixed wheelbase.Structural dynamics is used to deduce the analytical expressions of vertical vibration of simply supported beam under bidirectional moving loads. By simulation software MATLAB, the numerical result of the dynamic responses of simply supported beam bridge could be obtained. Then the 48 meters simply supported beam bridge in a high-speed railway is analyzed, the dynamic responses of simply supported beam of bidirectional moving loads with different interarrival times are discussed.Finally, some general laws for the design of double-line railway bridge are gained.


Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 83
Author(s):  
Gang Liu ◽  
Zongrui Hao ◽  
Yueshe Wang ◽  
Wanlong Ren

The dynamic responses of simply supported horizontal pipes conveying gas-liquid two-phase slug flow are explored. The intermittent characteristics of slug flow parameters are mainly considered to analyze the dynamic model of the piping system. The results show that the variations of the midpoint transverse displacement could vary from periodic-like motion to a kind of motion whose amplitude increases as time goes on if increasing the superficial gas velocity. Meanwhile, the dynamic responses have certain relations with the vibration acceleration. By analyzing the parameters in the power spectrum densities of vibration acceleration such as the number of predominant frequencies and the amplitude of each peak frequency, the dynamic behaviors of the piping system like periodicity could be calculated expediently.


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