• Journal of Aerospace System Engineering
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• v.6 no.4
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• pp.1-6
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• 2012

The morphing flap wing has different structure unliked general wing structure. The actuated chord length of the morphing flap was more longer than conventional wing flap. In this reason, morphing flap wing structure was important to bending moment by aerodynamic lift force. In this study, through the fluid-structure interaction using computational fluid dynamics and structure finite element analysis to apply that the morphing flap wing's static aeroelastic stability analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.264-267
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• 2001

by three-dimensional finite element method. The guide roll is an intermediately supported trans-axle miler, so called I-STAR roll, which was designed by VAI. The guide roll has been used in POSCO since 1998. Though the number of stowage in casting has been apparently decreased since thef it has occasionally been failed during operation. The simulations were carried out to find out the status of stress and deformation as well as improvement of the guide roll. The thermal effect is much more dominant than ferro-static pressure or others in stress and deformation of the guide roll. The material of the guide roll is SCM440.

• Bulletin of the Society of Naval Architects of Korea
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• v.19 no.2
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• pp.1-11
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• 1982

Ship bottom structure is idealized by an equivalent orthotropic plate upon which uniform lateral, uni-axial and bi-axial loads act. Solutions in the form of series representing deflections and moments at the center are obtained in case of simply supported and fixed boundary conditions. Variables in the solutions are reduced and grouped in nondimensional parameters. Stresses in the members of actual plate-stiffener combination are calculated corresponding to moments obtained above. In this paper design curves of deflections and moments for two different sets of boundary conditions are given, and they are compared with Schade's design curves and Mansour's design curves. Some examples for application are given and compared with the results obtained by FEM(SAPIV) in appendix.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.978-981
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• 2005

The vibration analysis of damped sandwich beam is conducted using finite element method. The equation of motion presented by Mead and Markus is used to formulate FEM. Also as the thickness of the core in the damped sandwich beam goes to zero, conventional beam theory based on the transformed-section method and the equation of Mead and Markus are compared. According to the change of thickness and loss factor of the core, the forced frequency response of beam is calculated and discussed. And then using the half-power band width method, the damping ratio of each mode is calculated and discussed about each case.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.78-83
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• 2009

In this study, computer applied engineering (CAE) techniques are fully used to conduct structural and dynamic analyses of a whole huge wind turbine system including composite blades, tower and nacelle. For this study, computational fluid dynamics (CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade model. Multi-body dynamic structural analyses are conducted based on the non-linear finite element method (FEM) by using super-element method for composite laminates blade. Three-dimensional finite element model of a wind turbine system is constructed including power train(main shaft, gear box, coupling, generator), bedplate and tower. The results for multi-body dynamic simulations on the wind turbine's critical operating conditions are presented in detail.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.618-621
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• 2001

The proposed lever actuator has no friction and mass balance characteristics in motion, which are adapt to high-speed and high-density optical disk system. This paper discussed about the theoretical analysis of the lever structure. The modeling of the lever actuator is found. Using the Newton's method, the motion of equation is deduced through the constraint equations and equilibrium equations in three directions (focusing, tracking and tilting). From the above analysis, we know that the shape of the hinge is the very important parameter on determining the performance of the lever actuator, and the actuator has the 2nd order system characteristics. And the first resonant frequency in transmissibility is dependent to the rigidity of the lever while the first transmissibility resonance of conventional actuators is dependent to the first natural resonance of those actuators. This means that the lever actuator is more stable to the external vibration.

• Journal of the Korean Ceramic Society
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• v.38 no.2
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• pp.193-198
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• 2001

유한요소법을 이용하여 STS VOD 래들에서 내장 내화물의 재질 및 back filler의 시공 위치에 따른 열응력을 수행하였다. 불소성 내화물의 경우 높은 열전도율에 의해 가동면과 배면(back face)간의 온도구배가 소성품에 비해 감소하였으며 탄성계수도 낮아 발생되는 열응력이 2~4배 낮았다. Back filler는 dolomite 내화물의 열간 팽창을 흡수하기 위해 시공하는 것으로, 상대적으로 낮은 열전도율을 가지고 있기 때문에 back filler의 내부와 외부에 급격한 온도구배가 발생된다. 결과적으로 래들의 내부는 고온을 유지하여 내화물이 팽창이 되고, 외부는 온도가 낮아지므로 수축되어 열응력이 증가하였다.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.453-457
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• 2011

In this study, transonic aeroelastic response analyses haw been conducted for the business jet aircraft configuration considering shockwave and flow separation effects. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to wing-body configurations. In transonic flight region, the characteristics of static and dynamic aeroelastic responses have been investigated for a typical wing-body configuration model. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.339-344
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• 2011

In the past much effort has been made to utilize advanced computational fluid dynamic (CFD) programs for aeroelastic simulations and analysis. However, it is limited in the field of unsteady aeroelasticity due to enormous size of computer memory and unreasonably long CPU time. Recently, AAEMS(Aerodynamics is Aeroelasticity minus Structure) was developed for linear time-invariant, coupled fluid-structure systems. In this paper, to demonstrate further the efficiency and accuracy of the new model reduction method, we successfully examine AGARD 445.6 wing modeled by FLUENT CFD, FSIPRO3D and NASTRAN FEM(Finite Element Method) programs. Using the ROM(Reduced Order Modeling) one can predict flutter boundary as a function of the dynamic pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.64-71
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• 2011

In this study, steady and unsteady aerodynamic analyses of a huge rocket configuration have been conducted in a transonic flow region. The launch vehicle structural response are coupled with the transonic flow state transitions at the nose of the payload fairing. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to the rocket configurations. Also, it is typically shown that the current computation approach can yield realistic and practical results for rocket design and test engineers.