• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.2
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• pp.141-151
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• 2003

Railway bridges are subject to dynamic loads generated by the interaction between moving vehicles and the bridge structures. These dynamic loads result in response fluctuations in bridge members. To investigate the real dynamic behavior of the bridge, therefore, a number of analytical and experimental Investigations should be carried out. In this paper, a train/track/bridge interaction analysis program for evaluating the dynamic characteristics of bridges due to KTX operation in terms of structural safety, operational safety and passenger comfort is developed. To build a practical model of train/track/bridge, Hertzian spring for wheel/rail contact modeling and Winkler element for ballast are applied. This program also used torsional degree of freedom and constraint equation based on geometrical relationship in order to take into consideration three-dimensional eccentricity effect due to the operation on double track through quasi-three dimensional analysis. To verify the developed Program, comparison has been made between the measured results and those of simulation of the typical PSC box bridge(2@40m=80m) of the KHSR bridges.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.56-62
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• 2003

The major noise source for the conventional train is the rolling noise caused by the interaction of the wheels and rails during the train passage on the tangent track. In order to control the rolling noise, the noise radiated from wheels, rails and sleepers should be analyzed and predicted. In this paper, a prediction method of wheel/rail rolling noise generated by the roughness of the wheel/rail surface is described, where the method is considering the effect of noise radiated by sleepers and the effect of ground. The method is applied to the Korean railway system, and the sound pressure level (SPL) predicted by the proposed method is compared with the measured SPL. Overall. the result shows good agreement between the predicted and measured values.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.817-820
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• 2014

지하철 인근 지역에서 차량 통과 시 차륜과 레일의 상호작용으로 인한 진동이 지반을 통하여 건물까지 전파되어 구조전달음이 발생하게 된다. 이러한 구조전달음이 발생하는 지하철 인근 지역에서 도로나 주거단지가 새롭게 조성될 예정인 경우, 완공 이후에 발생하는 구조전달음 영향을 사전에 평가하고 대책을 수립하는 것이 요구된다. 본 논문에서는 국내에 위치한 일부 역사에서의 구조전달음을 측정하고 국외의 예측식을 검토하여 구조전달음의 실측치와 예측치를 비교한다. 따라서 국내 지하철의 구조전달음 예측에 대하여 국외 예측식의 타당성을 검토함으로써 향후 건설될 지하구간 역사의 인근 주거지역에 대한 구조전달음을 예측하는데 기초 자료로 활용하고자 한다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.6-12
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• 2010

The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. The microphone array method is used to search sound radiation characteristics of elevated structure to predict the noise propagation from an elevated railway. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.671-678
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• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.4068-4076
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• 2013

The wheel-rail interaction forces are influenced by the velocity of vehicle, wheel load, alignment (curve radius, cant etc). For the safety of track structure, it is required to evaluate the influences for track and influential factors. Recently, the HEMU 430-X, which was developed by Next Generation High-Speed Rail Development R&D Project, achieved 421.4km/h in a test run of Daegu.Busan section of the Gyeongbu high speed rail on March in 2013. In the case of additional speed-up test on Test-Bed Section(Gongju.Jeongeup: KP 100~128km Osong starting point), the analysis of track forces is required for outer rail by the increase of dynamic force and centrifugal force of vehicle. In this paper, the vehicle speed variation on HSL line is evaluated by TPS analysis considering the tractive effort of HEMU 430-X, tested running resistance and alignment of Honam HSR. And the track forces are evaluated by centrifugal force and impact factor on curved track.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.517-522
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• 2021

In this study, the causes of damage to the concrete sleepers in a ballast track with under sleeper pads attached to the base of the sleepers installed in the sharp curved track(R=180m) of the urban railway bridge were analyzed. The damage types of concrete sleepers were investigated, and the correlation with track irregularity was reviewed. Also, stress generated in the concrete sleeper was reviewed through structural analysis. As a result, most of the cracks of the sleepers occurred in the section with severe track irregularity. In addition, as a result of the analysis, the stress generated in the track components and the sleepers was found to be reduce in the fastening system using the 4-anchor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.31-43
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• 2009

In this study, the numerical method is presented, which can consider the various train types and can solve the equations of motion for a vehicle-bridge interaction analysis by non-iteration procedure through formulating the coupled equations of motion. The coupled equations of motion for the vehicle-bridge interaction are solved by the Newmark ${\beta}$ of a direct integration method, and by composing the effective stiffness matrix and the effective force vector according to a analysis step, those can be solved with the same manner of the solving procedure of equilibrium equations in static analysis. Also, the effective stiffness matrix is reconstructed by the Skyline method for increasing the analysis effectiveness. The Cholesky's matrix decomposition scheme is applied to the analysis procedure for minimizing the numerical errors that can be generated in directly calculating the inverse matrix. The equations of motion for the conventional trains are derived, and the numerical models of the conventional trains are idealized by a set of linear springs and dashpots with 16 degrees of freedom. The bridge models are simplified by the 3 dimensional space frame element which is based on the Euler-Bernoulli theory. The rail irregularities of vertical and lateral directions are generated by the PSD functions of the Federal Railroad Administration (FRA). The results of the vehicle-bridge interaction analysis are verified by the experimental results for the railway plate girder bridges of a span length with 12 m, 18 m, and the experimental and analytical data are applied to the low pass filtering scheme, and the basis frequency of the filtering is a 2 times of the 1st fundamental frequency of a bridge bending.