• Proceedings of the KSR Conference
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• 2002.10b
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• pp.1059-1064
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• 2002

The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The load-deformation characteristics of ground and support are derived by the interaction between ground and support. The interaction between ground and support is qualitatively illustrated by a ground response curve. The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The interaction between ground and support is qualitatively illustrated by a ground response curve. The convergence-confinement method don't need the basic assumptions for a mathematical model. Also This is applicable to general tunnel. Consequently the stability of tunnel must be qualitatively investigated by a ground response curve and quantitatively adjudged by a numerical analysis for the reasonable design of tunnel.

• Journal of Ocean Engineering and Technology
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• v.9 no.2
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• pp.156-166
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• 1995

Regrading the development of offshore natural gas field near Sakhalin Island which is an ice-infested area, this study aims to estimate the dynamic ice load for construction of offshore structures operating in this region. In this paper the design ice load and dynamic responses of a slender Arctic structure upon continuous ice movement are sutdied. Crushing agter a certain elastic deformation is assumed as a primary failure mechanism at the contact zone between semi-infinite level ice edge and the face of structure. Dynamic interaction forces are calculated using a modified Korzhavin's equation and a two-dimensional ice-structure interaction model is adopted. To verify the numerical model, dynamic analysis is performed for on of the Baltic Sea channel markers whose response patterns were presiously observed.

• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.164-168
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• 2013

Tidal-current power is now recognized as a clean power resource. The turbine blade is the fundamental component of a tidal current power turbine. The kinetic energy available within a tidal current can be converted into rotational power by turbine blades. While in service, turbine blades are generally subjected to cyclic fatigue loading due to their rotation and the rotor-tower interaction. Predicting the fatigue life under a hydrodynamic fatigue load is very important to prevent blade failure while in service. To predict the fatigue life, hydrodynamic load data should be acquired. In this study, the vibration characteristics were analyzed based on three-dimensional unsteady simulations to obtain the cyclic fatigue load. Our results can be applied to the fatigue design of horizontal-axis tidal turbines.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.918-927
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• 2020

Flows induced by hybrid CRP pod propulsion systems (CRP-POD) are fundamentally characterized by unsteadiness. This work presents a numerical study on the unsteady flow of a CRP-POD at behind-hull condition based on CFD (Computational Fluid Dynamics). Unsteady RANS method is adopted, coupled with SST k-u turbulence model and sliding mesh method. The propeller thrusts and torques obtained by CFD is validated by model tests and acceptable agreements are obtained. The time histories of shingle-blade loads and pressures near the hull surface are recorded for the analysis of unsteady flow features. The cases of forward propeller alone and aft propeller alone are also computed to distinguish the hull-propeller interaction and propeller-propeller interaction. The results show the blade loads of both forward and aft propellers strongly fluctuate with phase angles. For the forward propeller, the blade load fluctuation is mainly governed by the hull-propeller interaction, while the aft blade load is remarkably affected by the propeller-propeller interaction in terms of the load average and fluctuation pattern. The fields of pressure, vorticity and velocity are also analyzed to reveal the unsteady flow features.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.674-678
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• 2003

This research is develop the sensing and measurement technology for measure that wheel/rail interaction force to use laser. Investigated existent laser measurement system, and examined transformation by load that action to wheel for achieve research purpose. A proposed to laser measurement system composition plan to analyze existent method that measure wheel/rail interaction force.

• Earthquakes and Structures
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• v.26 no.6
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• pp.477-487
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• 2024

The interaction between multiple structures through the supporting soil media, known as structure-soil-structure interaction (SSSI), has become an increasingly important issue due to rapid urbanization. There is a need to investigate the effect of SSSI on the structural response of buildings compared to non-interaction analysis (NIA) and soil-structure interaction (SSI) analysis. In the present study, two identical 4-bay×4-bay, three-story RCC buildings are modeled adjacent to each other with a soil domain beneath it to investigate the effect of SSSI on the forces experienced by footings under gravity and seismic load cases. The ANSYS software is used for modeling various non-interaction and interaction models which work on the principle of FEM. The results indicate that in most of the footings, the SSSI effect causes a significant redistribution of forces compared to SSI and NIA under both gravity and seismic load cases. The maximum interaction effect is observed on the footings that are closer to the adjacent building. The axial force, shear force and bending moment values on these footings show that SSI causes a significant increase in these values compared to non-interaction analysis but the presence of adjacent building relieves these forces significantly.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.29-35
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• 2008

This study is conducted to provide the proper analysis method to evaluate the stability of a container crane under wind load. Two analysis method, namely structure analysis and fluid-structure interaction, are adopted to evaluate the stability of a container crane in this investigation. To evaluate the effect of wind load on the stability of the crane, 50-ton class container crane widely used in container terminals is adopted for analysis model and 19-values are considered for wind direction as design parameter. We conduct structure analysis and fluid-structure interaction for a container crane with respect to the wind direction using ANSYS and CFX. Then we compare the uplift forces yielded from two analysis with it yielded from wind tunnel test. The results are as follows: 1) A correlation coefficient between structure analysis and wind tunnel test is lower than 0.65(as $0.29{\sim}0.57$), but between fluid-structure interaction and wind tunnel test is higher than 0.65(as $0.78{\sim}0.86$). 2) There is low correlation between structure analysis and wind tunnel test but very high correlation between fluid-structure interaction and wind tunnel test.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.41-42
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• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, analysis of coupling term between vertical load and lateral load for install load cell to wheel-set. This result is going to be utilized in formality that verify running safety of tilting vehicles.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.17-27
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• 2017

The treatment of rotor wake has been a critical issue in the field of the rotor aerodynamics. This paper presents a new free wake model for the unsteady analysis for a wind turbine. A blade-wake-tower interaction is major source of unsteady aerodynamic loading and noise on the wind turbine. However, this interaction can not be considered in conventional free wake model. Thus, the free wake model named Finite Vortex Element (FVE hereafter) was devised in order to consider the interaction effects. In this new free wake model, the wake-tower interaction was described by dividing one vortex filament into two vortex filaments, when the vortex filament collided with a tower. Each divided vortex filaments were remodeled to make vortex ring and horseshoe vortex to satisfy Kelvin's circulation theorem and Helmholtz's vortex theorem. This model was then used to predict aerodynamic load and wake geometry for the horizontal axis wind turbine. The results of the FVE model were compared with those of the conventional free wake model and the experimental results of SNU wind tunnel test and NREL wind tunnel test under various inflow velocity and yaw condition. The result of the FVE model showed better correlation with experimental data. It was certain that the tower interaction has a strong effect on the unsteady aerodynamic load of blades. Thus, the tower interaction needs to be taken into account for the unsteady load prediction. As a result, this research shows a potential of the FVE for an efficient and versatile numerical tool for unsteady loading analysis of a wind turbine.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.365-375
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• 2006

The structural analysis for the secondary lining of tunnels is generally performed by a frame analysis model. This model requires a ground loosening load estimated by some empirical methods, but the load is likely to be subjective and too large. The ground load acting on the secondary lining is due to the loss of the supporting function of the first support members such as shotcrete and rockbolts. Therefore, the equilibrium condition of the ground and the first support members should be considered to estimate the ground load acting on the secondary lining. Ground-lining interaction model, shortly GLI model, is developed on the basis of the concept that the secondary lining supports the ground deformation triggered by the loss of the support capacity of the first support members. Accordingly, the GLI model can take into account the ground load reflecting effectively not only the complex ground conditions but the installed conditions of the first support members. The load acting on the secondary lining besides the ground load includes the groundwater pressure and earthquake load. For the structural reinforcement of the secondary lining based on the ultimate strength design method, the factored load and various load combination should be considered. Since the GLI model has difficulty in dealing with the factored load, introduced in this study is the superposition principle in which the section moment and force of the secondary lining estimated for individual loads are multiplied by the load factors. Finally, the design method of the secondary lining using the GLI model is applied to the case of a shallow subway tunnel.