• 한국강구조학회 논문집
• /
• 제8권3호통권28호
• /
• pp.127-137
• /
• 1996

Connections as basic elements and an integrated part of a steel frame has an effect on the frame's performance. Conventional analysis and design techniques are based on either idealized fixed or pinned conditions. In fact, the use of rigid or pinned connection model in steel frame analysis serves the purpose of simplifying the analysis and design processes, but all connections used in current pratice possess stiffness and transfer moment which fall between the extreme cases of fully rigid and ideally pinned. To predict the behavior of the semi-rigid steel frames, it is necessary to predict the moment-rotation behavior of the beam-to-column connections. In this research, prediction equation for moment-rotation behavior of the beam-to-column connection is suggested and the effect of design parameters has investigated. Prediction model, in a nondimensional form shows the moment-rotation characteristic for connections. It is composed of the curve fitting power function using standardization constant K and 4 parameter $KM_o$, ${\theta}_0$, b, n based on the pretest result about moment-rotation behavior of connection.

• Steel and Composite Structures
• /
• 제1권2호
• /
• pp.187-200
• /
• 2001

Most of the portal frames are designed these days by the application of plastic analysis, with the normal assumption being made that the column bases are pinned. However, the couple produced by the compression action of the inner column flange and the tension in the holding down bolts will inevitably generate some moment resistance and rotational stiffness. Full-scale portal frame tests conducted during a previous research program had suggested that this moment can be as much as 20% of the moment of resistance of the column. The size of this moment of resistance is particularly important for the design of the tensile capacity of the holding down bolts and also the bearing resistance of the foundation. The present research program is aiming at defining this moment of resistance in simple design terms so that it could be included in the design of the frame. The investigation also included the study of the semi-rigid behaviour of the column base/foundation, which, to a certain extent, affects the overall loading capacity and stiffness of the portal frames. A series of column bases with various details were tested and were used to calibrate a finite element model which is able to simulate the action of the holding down bolts, the effect of the concrete foundation and the deformation of the base plate.

• 한국지진공학회논문집
• /
• 제28권1호
• /
• pp.11-20
• /
• 2024

The ductility of the system based on the capacity of each structural member constituting the seismic force-resisting system is a significant factor determining the structure's seismic performance. This study aims to provide a procedure to supplement the current seismic design criteria to secure the system's ductility and improve the seismic performance of the steel ordinary moment frames. For the study, a nonlinear analysis was performed on the 9- and 15-story model buildings, and the formation of collapse mechanisms and damage distribution for dynamic loads were analyzed. As a result of analyzing the nonlinear response and damage distribution of the steel ordinary moment frame, local collapse due to the concentration of structural damage was observed in the case where the influence of the higher mode was dominant. In this study, a procedure to improve the seismic performance and avoid inferior dynamic response was proposed by limiting the strength ratio of the column. The proposed procedure effectively improved the seismic performance of steel ordinary moment frames by reducing the probability of local collapse.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
• /
• pp.507-512
• /
• 2000

This paper presents a design procedure using the moment magnifier method that is applicable to RC flat plates subjected to combined axial compressive and uniform or non-uniform floor load. Based on the numerical results, the design values of the buckling coefficient and the effective flexural rigidity, that define the buckling force, have been proposed. Using these design values, this paper provides the design procedure for the moment magnifier method.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1097-1102
• /
• 2007

This paper describes the development of 6-axis force/moment sensor for an intelligent robot's foot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to a humanoid robot's foot(ankle). They in the published paper already have some disadvantage in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to be gotten similar the rated output under each rated load. So, the sensing elements of the 6-axis force/moment sensor should get lots of design variables. Also, the size of 6- axis force/moment sensor is very important for mounting to robot's foot. In this paper, a 6-axis force/moment sensor for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using FEM (Finite Element Method) analysis. Then, the 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

• International Journal of CAD/CAM
• /
• 제8권1호
• /
• pp.69-72
• /
• 2009

In this paper, we present a new shape descriptor, which is named Poisson equation-Fourier-Mellin moment Descriptor. We solve the Poisson equation in the shape area, and use the solution to get feature function, which are then integrated using Fourier-Mellin moment to represent the shape. This method develops the Poisson equation-geometric moment Descriptor proposed by Lena Gorelick, and keeps both advantages of Poisson equation-geometric moment and Fourier-Mellin moment. It is proved better than Poisson equation-geometric moment Descriptor in shape recognition and classification experiments.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2009년도 추계학술대회 논문집
• /
• pp.265-266
• /
• 2009

• 한국안전학회지
• /
• 제8권4호
• /
• pp.21-26
• /
• 1993

This paper presents a method of stress analysis of golf club. We define the sweet spot of golf club by the magnitude of torsional moment. Transfer matrix method was used for optimal design on sweet spot of golf club.

• 복합신소재구조학회 논문집
• /
• 제3권3호
• /
• pp.9-21
• /
• 2012

Concrete filled steel tube (CFT) columns have been widely used in moment resisting frame structures both in seismic zones. This paper discusses the design of such members based on the advanced methods introduced in the 2005 AISC Specification and the 2005 Seismic Provisions. This study focuses particularly on design following both linear and nonlinear methods utilizing equivalent static and dynamic loads for low-rise moment frames. The paper begins with an examination of the significance of pseudo-elastic design interaction equations and the plastic ductility demand ratios due to combined axial compressive force and bending moment in CFT members. Based on advanced computational simulations for a series of five-story composite moment frames, this paper then investigates both building performance and new techniques to evaluate building damage during a strong earthquake. It is shown that 2D equivalent static analyses can provide good design approximations to the force distributions in moment frames subjected to large inelastic lateral loads. Dynamic analyses utilizing strong ground motions generally produce higher strength ratios than those from equivalent static analyses, but on more localized basis. In addition, ductility ratios obtained from the nonlinear dynamic analysis are sufficient to detect which CFT columns undergo significant deformations.

• 한국강구조학회 논문집
• /
• 제20권4호
• /
• pp.469-481
• /
• 2008

연속경간 강합성 플레이트 거더교를 내측 교각 위 부모멘트부에서의 모멘트 재분배 효과를 고려하는 LRFD 비탄성설계법으로 설계하고 탄성설계법에 의한 설계결과와 비교하였다. 탄성 및 비탄성 설계 시에 교량은 3경간 연속교로 가정하였으며 경간비를 4:5:4로 중앙 경간 최대 경간장은 40m-70m를 고려하였다. 설계방법은 AASHTO-LRFD 규정을 적용하였으나 설계활하중은 최근 국내에서 새로이 제안된 활하중을 사용하였다. 탄성설계법으로 최대정모멘트 단면과 내측 교각 위 최대부모멘트 단면을 설계한 후에 내측 교각 위에서의 재분배모멘트를 계산하고 이를 최대정모멘트부의 설계모멘트에 추가하여 최대정모멘트부 단면에 대한 강도한계상태와 사용성한계상태에 대하여 검토하였다. 최대부모멘트부는 탄성설계법으로 구한 강거더 단면의 강재량을 감소시키고 비탄성설계법에 규정한 사용성한계상태 설계요구조건을 검토하였다. 5개의 연속교를 비탄성설계법으로 설계한 결과 최대부모멘트부의 강거더 단면적이 탄성설계에 비해 23% 내외 감소하는 것으로 분석되었다.