• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.67-76
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• 1992

A procedure to determine the axle load limits of asphalt concrete pavements are proposed in this study. Axle load limits are determined by calculating maximum tensile strains at the bottom of the asphalt stabilized base layer and maximum vertical strains at the top of the subgrade. In order to investigate the efficiency of axle configuration, calculated influence line of wheel load on domestic expressway pavement system is used. Limiting strains are selected through the analysis of conventional failure criteria. From the analysis of axle load limits about axle composition(single-axle, tandem-axle, tridem-axle), it is found that the axle load limits of tandem-axle and tridem-axle can be calculated by muitipling the axle load limits of single-axle by axle numbers and that axle load limits are closely related to the thickness of each layer of pavement structure. It is also found that the axle load limits by tensile strains are more critical than those by vertical strains on asphalt concrete pavement models of YOUNG-DONG, KYONG-IN and KYONG-BU expressways.

• Journal of the Korean Society for Advanced Composite Structures
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• v.4 no.4
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• pp.22-29
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• 2013

Accumulation of more than 20,000,000 vehicles since the establishment of the quality of life and economic development needs several parking lots and cause crack problem in Korea. Related structures in large cities due to the lack of parking garage attached to secure underground parking structures are actively being built, and the basement parking lot will continue to increase more stories and the trend is expected to be larger. But so far, construction of the underground parking structure is related to a number of problems, including cracks in the structure. Therefore, in this study, repair, reinforcement and a few non-economic losses in the current design criteria are presented. The review of the structure used to current design criteria is to minimize crack and maximize usability.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.39-45
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• 2008

The most important elements in flexible pavement design criteria are stress and strain distributions. To obtain reasonable stress and strain distributions in pavements, moving wheel loads must be applied to analyze the pavement responses. In this study, finite element analysis was used to identify the three-dimensional states using the vehicle load into a constant-position / time-variable load (25, 50 and 80km/hr). In an elastic system, the strain is the same in both longitudinal and transverse directions under a single wheel. However, the same is not necessary in a viscoelastic system. Test results showed that the maximum values between transverse and longitudinal strains the bottom of asphalt concrete base layers under 25km/hr were were about 40 percent.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.481-484
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• 2011

최근 철도는 미래의 핵심교통수단이자 저탄소 녹색성장을 대표하는 교통수단으로 주목받고 있다. 그 중 자기부상열차는 바퀴 마찰에 따른 소음 진동 분진이 없는 차세대 교통수단이며, 이를 지지하는 구조물(교량)은 열차의 운행 안정성(동적거동)을 고려한 설계가 필요하다. 또한, 상부 구조물은 자기부상열차의 연행이동등분포하중을 지지하며, 이러한 하중조건을 갖는 차량이 운행할 때 상부 구조물은 설계기준사항들을 만족해야한다. 도시형 자기부상철도 토목구조물 설계기준에 의하면 도시형 자기부상철도의 운행 안정성(동적거동)을 평가하기 위한 항목들로 대상 구조물의 고유진동수, 승차감을 고려한 연직처짐 등이 요구된다. 따라서, 본 연구에서는 자기부상열차의 실 열차하중을 고려하여 연행이동등분포하중으로 철도교량의 동적거동을 검토하였으며, 설계기준을 적용하여 대상 철도 교량의 운행 안정성을 평가하였다.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.727-736
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• 2000

The present study investigates the influences of vehicle induced loads on the thermal buckling behavior of straight and curved continuous welded rail (CWR) tracks. Quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deflection induced by wheel loads of vehicle. The lateral loads of vehicle induced by weight, the speed, the superelevation and curvature of track, and other dynamic vehicle track interaction, are included in the ratio of lateral to vertical vehicle load. Parametric numerical analyses are perfomed to calculate the upper and lower critical buckling temperatures of CWR tracks, and the comparison between the results of this work and the previous results without vehicle is also included.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.45-55
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• 2023

This study conducted aeromechanics modeling and structural load analyses of Tilt Rotor Aeroacoustic Model (TRAM), a 25% scaled V-22 tiltrotor model used in wind tunnel tests. A rotorcraft comprehensive analysis code, CAMRAD II, was used. Analysis results of this study in low-speed forward flights were compared with DNW test and previous analysis results. Blade flap bending moments were in good agreement with measured data. Mean values and oscillatory loads for lead-lag bending and torsion moments were slightly different from measured data. However, when mean values were removed, results of structural loads for one rotor revolution were moderately compared with wind tunnel tests and previous analyses. Total forces and half peak-to-peak forces of the pitch link reasonably well matched with previous analysis results and measured data. Finally, harmonic magnitudes of blade structural loads were investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.250-256
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• 2010

In this paper, an analytical and experimental study is performed in order to determine the effects of interaction between vehicle and bridge superstructure. For this purpose an improved wheel tracking machine and an adequate single span bridge are designed. Results presented in the paper show that wheel tracking machine including moving mass effects can demonstrate more accurate dynamic interaction between vehicle and structure.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.451-458
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• 2012

This study aims at the structural analysis with fatigue according to the configuration of railway vehicle wheel. Maximum equivalent stress or deformation is shown at the lower face in contact with wheel and rail. As model B has the maximum stress or deformation which becomes lower than model A, model B is shown to have more durability than model A. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-10^{11}$ Pa and the amplitude stress of 0 to $10^{10}$ Pa, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of railway vehicle wheel by prevention and durability against its damage.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2464-2472
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• 2011

Train runs on high speed and the concrete track is constructed. Rail fastening device needs to reduce elasticity, transferred load, noise, and vibration etc. Consequently, low elastic pad has a great impact of the durability and stability of the track. In this study, discussed in previous studies, static numerical analysis and real scale repeated loading test, followed by dynamic response analysis were implemented. The most distinctive characteristics of the model proposed is to simulate the real wheel behavior on rail. And the main analysis object is to evaluate and compare the deformation characteristics of the transition track while load reduction effect of transfer on roadbed assessed by various low elastic pad.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.761-769
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• 1994

Actual load acting on rail surface in the track is the combined mode loading due to the contact rolling load of the wheels. To investigate the fracture behavior on rail steel under combined modes I and II, fracture tests were performed by using the test jigs and fracture specimen which were designed by Richard. The analysis results of experimental fracture data were compared with various fracture criteria that have been introduced for determination of the crack propagation direction and the critical stress of fracture of a crack submitted to a mixed mode loading. From the results, it was shown that the actual crack propagation direction of rail steel agree with the crack propagation directions predicted by maximum tangential stress criterion and strain energy density criterion, and that fracture criterion follows principal strain criterion.