• Journal of Korean Society of Steel Construction
• /
• v.12 no.5 s.48
• /
• pp.595-604
• /
• 2000

Web openings of large beams provide space for wiring, piping, and duct work to provide for proper drainage, pipes and duct must be slightly sloped with the attendant result that all web openings can not be centered on the centroidal axes of the beams. Test specimens are made for opening-depth to beam-depth ratio of 0.5 and for eccentricities of the opening center line of 10% from middepth of the beam because of the proximity of the opening edge to the flange. In this paper, available test results and theories relating to the strength of composite beams having eccentric rectangular openings are surveyed and experiments were carried out to examine the structural behaviors. In all the tests in this paper good agreement is demonstrated with maximum loads measured in tests, and observed failure modes Furthermore, compared with analytical values and experimental values of interaction diagram between moment and shear capacity were safed as it is scattered with outer part of the analytical values.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.1
• /
• pp.1-9
• /
• 2010

Pile reinforcement systems with enlarged upper section are newly introduced by using a mechanism that most of horizontal forces are resisted in the upper part of the pile. The new systems are expected to be effectively applicable to the marine structures including port and harbor facilities. In this study, three different reinforcement methods such as bucket pile type, top base pile type, and grouting reinforcement type were utilized in the 3-D. numerical simulations. The parametric study deals with the effects of various factors including soil types and stratigraphy, reinforcement methods, type and dimension of the pile on the lateral behaviors of the pile. The results show that the reinforcement method with bucket pile is the most efficient one compared to the top base pile type and grouting reinforcement type.

• Computational Structural Engineering
• /
• v.9 no.1
• /
• pp.115-123
• /
• 1996

This paper was developed to computer program, which is about to analyize nonlinear behavior of structural member and frame including to geometric and material nonlineality, and formulated to the relationship of stress-strain of steel. In order to examplity the efficiency of this program, the numerical analysis was done for H section steel beam and square steel tube column subjected to monotonic load, and braced steel frame subjected to repeated horizontal forces. The obtained results by this program were in accordance with existing experimental and analytical results respectively.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.1
• /
• pp.82-88
• /
• 2002

This paper deals with the free vibrations of horizontally curved beams with transition curve. Based on the dynamic equilibrium equations of a curved beam element subjected to the stress resultants and inertia forces, the governing differential equations are derived for the out-of-plane vibration of curved beam wish variable curvature. This equations are applied to the beam having transition curve in which the third parabolic curve is chosen in this study. The differential equations are solved by the numerical procedures for calculating the natural frequencies. As the numerical results, the various parametric studies effecting on natural frequencies are investigated and its results are presented in tables and figures. Also the laboratory scaled experiments were conducted for verifying the theories developed herein.

• Journal of Korean Association for Spatial Structures
• /
• v.10 no.2
• /
• pp.69-76
• /
• 2010

After obtaining tensile and compressive stiffness as well as shear stiffness of elastomeric seismic isolator experimentally, those stiffness were modeled analytically using nonlinear computer program. To induce tensile stress due to overturning in the seismic isolators of an isolated frame for horizontal force, free vibration simulations generated by large initial displacement were conducted. Since elastomeric seismic isolator is weak for tensile stress, the axial stiffness of isolators shall be included properly in the analytical model to evaluate the uplift phenomenon of elastomeric seismic isolator.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.411-416
• /
• 2000

The behavior of high strength reinforced concrete columns subjected to uniaxal reversal loading and biaxial reversal circle path loading was investigated. Four full scale test specimens were tested. All specimens were adopted cantilever type, in order that the critical region is to locate only at the bottom of column. The parameters studied were transverse reinforcement ratio, uniaxial lateral loading and biaxial lateral loading. The damage features of columns by the biaxial loading are different from those of the uniaxial loading, However, the maximum strength and the draft angle at maximum strength were almost the same under uniaxial and biaxial loading. The transverse reinforcement under biaxial loading was very effective for increasing ductility of specimens.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.326-333
• /
• 2004

This paper presents the structural characteristics analysis of a high-speed horizontal machining center with spindle speed of 50, 000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motor and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guide. The structural analysis model of the high-speed horizontal machining center is constructed by the finite element method, and the validity of structural design is estimated based on the structural deformation of the high-speed horizontal machining center and spindle nose caused by the gravity and inertia forces.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.1
• /
• pp.1-9
• /
• 2004

In this paper, an efficient modeling method of Horizontal-Axis Wind Turbine(HAWT) system is proposed. This method Is based on representing a HAWT system as a multi-body system with several rigid bodies i.e. rotor blade, low/high speed shaft, gear system, md generator. Also, simulation software WINSIM is developed to evaluate performance of wind turbine system. Simulation results show that the proposed modeling method and simulation software are efficient and reliable.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.255-258
• /
• 2010

최근 초고층 구조물은 다양한 형태에 따른 건축 계획 및 설계에 대한 요구되어지며 이를 충족시키기 위해 다양한 구조시스템이 개발되어지고 있다. 특히 경사기둥은 구조물의 높이가 증가할수록 구조물의 면적이 점차적으로 감소하는 Tapered 형태의 비정형 초고층 구조물의 중요한 설계 및 구조요소이다. 본 논문에서는 경사기둥의 축하중에 의해 발생하는 수평력으로 인한 접합부의 영향 및 보 플랜지의 취성파괴에 대한 저항성능을 평가하기 위하여 강구조물 경사기둥 접합부에 대한 유한요소해석을 수행하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.775-779
• /
• 2001

In optical disk drive (ODD), disk rotation speed has been increasing rapidly to achieve high data transfer rate. High servo bandwidths for focusing and tracking actuator are required to follow dynamic disturbance by high rotation speed in ODD. However, the servo bandwidth is significantly limited by some vibration modes which are induced by the flexibility of moving part. In this work, the vibration modes affecting bandwidth of actuators are suppressed by modifying actuating force by VCM. For this, the relation between the horizontal component of the actuating force and vibration mode is analyzed and force characteristic affecting to vibration mode is obtained through electromagnetic and structural analysis using simulation program.