• Structural Engineering and Mechanics
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• v.77 no.5
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• pp.627-635
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• 2021

The speed of rail vehicles become higher and higher over two decades, and China has unveiled a prototype high-speed train in October 2020 that has been able to reach 400 km/h. At such high speeds, wheel-rail force items that had previously been ignored in common computational model should be reevaluated and reconsidered. Aiming at this problem, a new model for investigating the vehicle-bridge interaction at high moving speed is proposed. Comparing with the common model, the new model was more accurate and applicable, because it additionally considers the second-order pseudo-inertia forces effect and its modeling equilibrium position was based on the initial deformed curve of bridge, which could include the influences of temperature, pre-camber, shrinkage and creep deformation, and pier uneven settlement, etc. Taking 5 km/h as the speed interval, the dynamic responses of the classical vehicle-bridge system in the speed range of 5 km/h to 400 km/h are studied. The results show that ignoring the second-order pseudo-inertia force will underestimate the dynamic response of vehicle-bridge system and make the high-speed railway bridge structure design unsafe.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.91-96
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• 2008

As a remarkable reduction of the vehicle noise, the important of tire noise which is generated from the vehicle and the necessity of the research for the noise reduction is being emphasized. In this study, the road noise which is excited by the interaction between tire and road has been studied. The subjective test(feeling test) according to SAE J1060 rating scale is applied to the evaluation of the road noise. The combination of the several tires and vehicles are made to consider the effect of the vehicle suspension and the tire structure for road noise. The vehicles with 3-different suspension system are applied to road noise test and the eight kinds of tires are selected. As the results, the effects of the vehicle suspension and tire structure which affects on road noise are investigated.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.324-327
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• 2011

The design requirement for ground mounted sign structures are fairly well defined in the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals and consists of applying an equivalent pseudo-dynamic loading to account for the dynamic effects of wind loads and ignores the dynamic effect due to moving vehicle loads. This design approach, however, should not be applied to the design of bridge mounted sign structures because ignoring the dynamic effects of the moving vehicle loads may produce non-conservative results, since the stiffness of the bridge structure can greatly influence the behavior. Not enough information is available in the literatures which provide guide lines to include the influence of moving vehicles in the design of the bridge mounted sign structures. This paper describes a theoretical methodology, Bridge-Vehicle Interaction Element, which can be utilized to account for the dynamic effect of moving vehicles. A case study is also included where this methodology was successfully applied. It was concluded that the bridge-vehicle interaction finite element developed can provide a more accurate representation of the behavior of bridge mounted sign structures. The result of these analysis enabled development of simple and effective retrofitting scheme for the existing support system of bridge-mounted-structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.357-361
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• 2003

According to the remarkable reduction of the vehicle noise, the important of tire noise which is generated from the vehicle and the necessities of the researches for the noise reduction are emphasized. In this study, we have studied the road noise which is excited by the interaction between tire and road. In order to evaluate the road noise, we carry out the subjective test(feeling test). In order to consider the effect of the vehicle suspension for the tire/road noise, we are equipped with identical tires on the differential vehicle suspension and evaluate the road noise. In order to consider the effect of the tire structure for the tire/road noise, we evaluate the some tires with various structures. From the test results, we fine that the difference of road noise is generated by the variation of the vehicle suspension. Also, we can select the optimized tire structure which can be reduced the road noise.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.873-881
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• 2002

The fluid induced vibration (FIV) phenomena of an equivalent airfoil system of MAV have been investigated in low Reynolds number flow region. Unsteady flows with viscosity are computed using two-dimensional incompressible Navier-Stokes equations. The present fluid/structure interaction analysis is based on one of the most accurate computational approach with computational fluid dynamics (CFD) and computational structural dynamics (CSD) techniques. The highly nonlinear fluid/structure interaction phenomena due to severe flow separations have been analyzed for the low Reynolds region that has a dominancy of flow viscosity. The effects of Reynolds number and initial angle of attack on the fluid/structure coupled vibration instability are shown and the qualitative trend of FIV phenomenon is investigated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.10-13
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• 2002

Pogo is the instability resulting from the interaction between rocket structure and propulsion system of liquid propellant rocket. The coupling of structure and propulsion system can lead to severe problem in rocket. For the analysis of pogo, a time-invariant linearized mathematical model is developed for a selected flight time. Propulsion system is modeled using element representations for each components. The constitutive equation of propulsion system is a homogeneous second-order equation form in the Laplace domain. Rocket structure is modeled using FEM. From the results of modal analysis of structure, the behavior of structure can be represented. System equations for coupling structure and propulsion system are composed of all propulsion system equations and vehicle motion equations reacting on the vehicle by each component of propulsion system. The stability is obtained by the eigen solution of system matrix. The optimization of the design variables such as size, place of accumulator for suppressing pogo instability is carried out. This article of study can be used to determine the degree of stability, and guide the design of pogo suppression system.

• 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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.216-223
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• 2023

As the technology and level of autonomous vehicles advance and they drive in more diverse road environments, an intuitive and efficient interaction system is needed to resolve and respond to the situations the vehicle faces. The development of driving technology from the perspective of autonomous driving has the ultimate goal of responding to situations involving humans or more. In particular, in complex road environments where mutual concessions must be made, the role of a system that can respond flexibly through efficient communication methods to understand each other's situation between vehicles or between pedestrians and vehicles is important. In order to resolve the status of the vehicle or the situation being faced, the provision and method of information must be intuitive and the efficient operation of an autonomous vehicle through interaction with intention is required. In this paper, we explain the vehicle structure and functions that can display information about the situation in which the autonomous vehicle driving in a living lab can drive stably and efficiently in a diverse and complex environment.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.103-108
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• 2014

Growing concerns about environmental pollution have led to an increase in the demand for compressed natural gas (CNG) vehicles in recent years. CNG vehicles are equipped with a cylinder valve installed in a high-pressure vessel to control the CNG flow. The cylinder valve must meet high quality safety standards because the pressure vessel stores high-pressure CNG. Therefore, safety evaluation of the cylinder valve is necessary to ensure the safety of CNG vehicles. In this study, fluid-structure interaction analysis for the structural integrity of the cylinder valve were conducted using a commercial finite element analysis code(ANSYS WORKBENCH V14). The CFD analysis was performed using a steady-state technique according to the inlet and outlet pressures in order to predict the pressure distribution. Structural analysis was performed by a static structure technique at the maximum working pressure to evaluate the structural integrity of the cylinder valve. From the results, the safety factor of the valve component is between 1.57 and 21.5.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.6
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• pp.367-374
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• 2020

A standard for the vibration magnitude of a maglev train is presented herein to ensure a comfortable ride for the passengers. The vibration magnitude is determined from the vertical acceleration of the car body. A parameter analysis of the maglev train system is then performed considering the vehicle-structure interaction, and a deflection limit of L/1300 is proposed to satisfy the standard for the vertical acceleration. The proposed deflection limit is applied to the dynamic analysis of the actual maglev train system to assess applicability. Compared with the existing standard for the guideway structure, the proposed deflection limit is expected to enable economical design and construction.