• Journal of Ship and Ocean Technology
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• v.6 no.3
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• pp.1-12
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• 2002

In this paper the results are reported of sixty-nine lateral collision tests, which were performed to investigate the collision resistance of plates. For the tests a collision testing machine of spring-roller conveyer type was designed and fabricated. Using this machine, various plates were tested with different masses and velocities and various headers of the striker. A simple analytical method has also been developed to predict the extent of damage of struck plates due to lateral collision. In the method, it is assumed that the kinetic energy of the striker can be dissipated by the formation of yield lines and membrane tensions in the impacted plate. The calculated predictions of extent of damage using the developed method have been substantiated with the test results, which shows reasonably acceptable correlations.

• Wind and Structures
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• v.15 no.3
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• pp.263-283
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• 2012

This paper presents a framework of nonlinear dynamic analysis of a low-speed moving maglev (magnetically levitated) vehicle subjected to cross winds and controlled using a clipped-LQR actuator with time delay compensation. A four degrees-of-freedom (4-DOFs) maglev-vehicle equipped with an onboard PID (Proportional-Integral-Derivative) controller traveling over guideway girders was developed to regulate the electric current and control voltage. With this maglev-vehicle/guideway model, dynamic interaction analysis of a low-speed maglev vehicle with guideway girders was conducted using an iterative approach. Considering the time-delay issue of unsynchronized tuning forces in control process, a clipped-LQR actuator with time-delay compensation is developed to improve control effectiveness of lateral vibration of the running maglev vehicle in cross winds. Numerical simulations demonstrate that although the lateral response of the maglev vehicle moving in cross winds would be amplified significantly, the present clipped-LQR controller exhibits its control performance in suppressing the lateral vibration of the vehicle.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.1042-1048
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• 2016

This paper presents a lateral displacement restoring force control for the independently rotating wheelsets (IRWs) of shallow-depth subway systems. In the case of the near surface transit, which has recently been introduced, sharp curved driving performance is required for the city center service. It is possible to decrease the curve radius and to improve the performance of the straight running with the individual torque control. Therefore, the individual torque control performance of the motor is the most important point of the near surface transit. This paper deals with a lateral displacement restoring force control for sharp curved driving. The validity and usefulness of the proposed control algorithm is verified by experimental results using a small-scale bogie system.

• Steel and Composite Structures
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• v.43 no.2
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• pp.165-183
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• 2022

Most transportation departments have recognized and developed procedures to address the ever-increasing weights of trucks traveling on bridges in a service today. Transportation agencies also recognize the issues with overheight vehicles' collisions with bridges, but few stakeholders have definitive countermeasures. Bridges are becoming more vulnerable to collisions from overheight vehicles. The exact response under lateral impact force is difficult to predict. In this paper, nonlinear impact analysis shows that the degree of deformation recorded through the modeling of the unprotected vehicle-girder model provides realistic results compared to the observation from the US-61 bridge overheight vehicle impact. The predicted displacements are 0.229 m, 0.161 m, and 0.271 m in the girder bottom flange (lateral), bottom flange (vertical), and web (lateral) deformations, respectively, due to a truck traveling at 112.65 km/h. With such large deformations, the integrity of an impacted bridge becomes jeopardized, which in most cases requires closing the bridge for safety reasons and a need for rehabilitation. We proposed different sacrificial cushion systems to dissipate the energy of an overheight vehicle impact. The goal was to design and tune a suitable energy absorbing system that can protect the bridge and possibly reduce stresses in the overheight vehicle, minimizing the consequences of an impact. A material representing a Sorbothane high impact rubber was chosen and modeled in ANSYS. Out of three sacrificial schemes, a sandwich system is the best in protecting both the bridge and the overheight vehicle. The mitigation system reduced the lateral deflection in the bottom flange by 89%. The system decreased the stresses in the bridge girder and the top portion of the vehicle by 82% and 25%, respectively. The results reveal the capability of the proposed sacrificial system as an effective mitigation system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.10 no.1
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• pp.69-82
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• 2002

Recently, it appears that the major change in open skies agreement established the bilateral agreement and sub-regional multi-lateral agreement system with U.S.A. as the central figure. Specifically sub-regional multi-lateral air transportation cooperation is based on the bilateral agreement systems among the like minded countries. To develop the air transportation industry, Each country tries to come true free air transportation in bloc and deregulation in terms of market approach and traffic right. The purpose of this study is to look into the background of sub-regional air transportation cooperation and to expect the economic impact of the open skies agreement. We selected the Singapore in Asia-Pacific region as the subject of investigation. Even though Singapore is a small country in Asia-Pacific region. They have global competition power which is airport field as well as to airlines and tourism industry. Under this condition, we analyzed the economic impact of the open skies policy through the Input/Output analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.310-316
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• 2016

We propose a novel contact-free transportation system in which an axial electrodynamic wheel is applied as an actuator. When the electrodynamic wheel is partially overlapped by a fixed conductive plate and rotates over it, three-axis magnetic forces are generated on the wheel. Among these forces, those in the gravitational direction and the lateral direction are inherently stable. Therefore, only the force in the longitudinal direction needs to be controlled to guarantee spatial stability of the wheel. The electrodynamic wheel consists of permanent magnets that are repeated and polarized periodically along the circumferential direction. The basic geometric configuration and the pole number of the wheel influence the stability margin of a transportation system, which would include several wheels. The overlap region between the wheel and the conductive plate is a dominant factor affecting the stiffness in the lateral direction. Therefore, sensitivity analysis for the major parameters of the wheel mechanism was performed using a finite element tool. The system was manufactured based on the obtained design values, and the passive stability of a moving object with the wheels was verified experimentally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.53-59
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• 2019

To reduce the vibrations and shocks during the cargo transportation of high value-added goods, the vibration history was measured on the truck transportation section (Asan-Uiwang) and the freight train transportation section (Uiwang-Pusan). The internal vibrations of the container were obtained by attaching acceleration sensors in three axis directions (longitudinal, lateral. and vertical directions) on the front and rear bogies. The rail vibration profile (0.29Grms) proposed in ASTM D-4169 was approximately 50% higher than the truck vibration profile (0.54Grms). The overall vibration was 16% and 33 % lower in the longitudinal and transverse directions, respectively, compared to the ASTM truck transport vibration profile. On the other hand, the vertical vibration measurement history partially exceeded the ASTM truck transport vibration profile over the range, 4 - 15Hz, and over 60Hz. The vibration measurement history of the cargo train was similar to that of the road. The longitudinal and lateral vibration history was lower than the ASTM D-4169 rail vibration profile, while the vertical history was over 30Hz.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.43-55
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• 2017

The purpose of this study is to investigate the effect of traffic loads on retaining wall stability. There is insufficient research on lateral earth pressure on retaining wall due to traffic load. In addition, limited detailed designs of retaining wall for transportation including number of lanes of road, magnitudes of axle loads, and vehicle formations are available. Because the lateral earth pressure on the retaining wall due to traffic loads is a function of the lateral distance from retaining wall, the wall height, and the locations of lanes, the analysis of lateral load on retaining wall from traffic loads is performed with direct or indirect reflection of these factors. As a result of the analysis, lateral earth loads induced from traffics can be considered negligible if the lateral distance of traffic load from wall exceeds the height of retaining wall. Therefore, it is practically reasonable to consider traffic loads within a lateral distance between wall and traffic load of the height of retaining wall.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.645-646
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• 2015

The conventional wheelsets has disadvantages of potential oscillatory instability. In the paper, a design of the permanent magnet synchronous machine of independent-wheel type for near-surface is performed. Also, the lateral displacement control algorithm is proposed. The subcale bogie can maintain the centering by this algorithm. The design of the machine is verified by BEMF. And the validity and usefulness of the lateral displacement control algorithm is verified by experimental results.

• International Journal of Railway
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• v.5 no.4
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• pp.156-162
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• 2012

When a vehicle passes through turnout, it is required to minimize the changes of lateral force for running safety of vehicle. Therefore, it is necessary to analyze interaction between the vehicle and the turnout in order to estimate the lateral force and the derailment coefficient on the turnout. In this paper, analysis model of the vehicle and turnout are established and analysis is carried out when the vehicle passes through turnout in order to improve running safety of the vehicle on turnout. To verify the vehicle and turnout analysis model, the contact points between wheel and rail and the influence of changing cradle and tongue rail are also discussed.