• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.04b
• /
• pp.475-480
• /
• 1998

The composite framed structures, consisting of RC columns and steel beams more popular in korea because of their efficiency and quality. However the force transfer mechanisms between the column and beam may by very complicated since the materials of columns and beams are different. This study develops "the column penetration joint" which the web of steel beam doesn't penetrate and which could improve the strength, deformation, and energy dissipation capacities compared to existing composite joints. It is the concrete-filled square tube joint with the exterior diaphragms and the cruciform stiffening plates. This study evaluated the strength of RC column penetration to steel beam connection by analyzing the results of partial experiments, and reviewed the applicability the strength formula through the comparison of tested results of joint experiment.

• Computational Structural Engineering
• /
• v.11 no.4
• /
• pp.371-382
• /
• 1998

지난 수 십년 간 컴퓨터는 구조설계에 있어서 그 이용이 증가하고 있다. 구조설계를 위한 컴퓨터 시스템을 개발하기 위해서는 먼저 구조설계에 관련된 정보와 작업을 정형화한 표현이 필요하다. 본 논문은 구조설계에서 설계정보와 설계작업의 이해와 표현이 어려운 분야의 하나인 시스템설계에 대하여 논하고 있으며, 빌딩 프레임구조물의 시스템 설계정보를 표현하는 한 방법을 기술하고 있다. 3차원 공간을 표시하기 위하여 기준평면과 그리드 라인을 정의하였으며, 빌딩 프레임구조물의 시스템을 프레임 서브시스템, 플로어 서브시스템, 시스템요소 기둥의 세 종류의 요소로 분해하였다. 시스템요소 기둥은 프레임의 요소가 아니고, 시스템의 요소이다. 시스템 설계정보를 표현하기 위한 이와 같은 방법을 개체형 통합설계모델의 표기법을 이용하여 표시하였다. 개체형 통합설계모델은 설계정보와 설계작업을 표현하기 위하여 각각 프로덕트 개체와 프로세스 개체를 이용한다. 시스템 설계정보를 위하여 본 논문에서 정의한 프로덕트 개체들은 정형화된 시스템 설계정보를 표현하는데, 이것은 구조설계 CAD 시스템 개발에 유용하다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.6A
• /
• pp.827-833
• /
• 2008

This paper deals with the free vibrations of elastica shaped arches. The elastica shaped arches are formed by the post-buckled column whose arc length is always constant. The equations governing free, planar vibration of general arch in open literature are modified for applying the free vibrations of elastica shaped arch and solved numerically to obtain frequencies and mode shapes for hinged-hinged, clamped-hinged and clamped-clamped end constraints. The effects of rotatory inertia, rise ratio and slenderness ratio on natural frequencies are presented. The frequencies of elastica shaped arches are greater than those of parabolic shaped ones. Also, typical mode shapes are presented in figures.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3A
• /
• pp.265-275
• /
• 2010

Concrete filled steel tube and concrete encased steel tube columns are expected to have confined effects of concrete by steel and reinforced effects of local buckling by concrete. On the basis of confined state concrete models of previous researches, stress-strain and load-displacement relations of RC, CFT and CET columns are analyzed by steel ratio. After comparing analysis results with experimental results, Modified stress-strain relations are derived through evaluation the influence upon confined effects of concrete in each cases. Also, the modified stress-strain models are carried out to be compared with specified strength of various countries.

• Journal of the Korea Concrete Institute
• /
• v.17 no.1 s.85
• /
• pp.85-94
• /
• 2005

Post-tensioned Precast concrete System(PPS) consists of U-shaped precast wide beams and concrete column. The continuity of beam-column joint is provided with floor concrete cast on the PC shell beam and post-tensioning. The purpose of this paper is to evaluate the response of PPS interior beam-column joint subjected to cyclic lateral loading. To this end, an experimental investigation was performed with three half-scale specimens of interior connection. The design parameters are the amount of beam reinforcement placed inside the joint core. The test results showed that cracks were distributed well without my significant degradation of strength and ductility. Also, it was found that the prestressing may affect to alter the torsional crack angle. And the specimens sufficiently resist up to limiting drift ratio of 0.035 in accordance with the provisional by ACl of acceptance criteria for concrete special moment frames.

• Journal of Korean Society of Steel Construction
• /
• v.27 no.5
• /
• pp.471-481
• /
• 2015

Modular building is a prefabricated construction system for building where factory-produced pre-engineered modular units are delivered to site and assembled as substantial elements of a building. There are two basic kinds of modular structures. One is a load-bearing wall structure designed to transfer the load through longitudinal walls. The other is a frame structure composed of columns and beams. For frame structure, square hollow section is often used as a column member and channel as a beam member in modular unit. Lower and upper modules are fasten with bolts via a pre-installed access hole in the SHS column. However, the access holes can weaken the panel zone that would affect the behavior of beam to column connection. The 5 specimens of beam to column connections with parameters of access hole, column thickness and diaphragm were made and this paper describes the test results.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.598-601
• /
• 1995

This paper proposes a federated Kalman filter approach which utilizes information from multiple sensors and variable estimation model. Compared with the decentralized Kalman filter, the algorithm proposed in this paper demonstrates much better tracking performance in both maneuvering and constant velocity movement of the target.

• Journal of Korean Society of Steel Construction
• /
• v.22 no.5
• /
• pp.497-509
• /
• 2010

Five concrete-encased steel columns using high-strength steel($f_{ys}$=801MPa) and high-strength concrete($f_{ck}$=97.7MPa) were tested to investigate the eccentric axial load-displacement relationship. Test parameters included the type, yield strength, and spacing of lateral reinforcement, and also the eccentricity of axial load. To analyze the behavior of the column specimens, the nonlinear sectional analysis using strain-compatibility and confinement effect was performed. To examine the applicability of existing design codes for the composite sections using high-strength materials, the test results were also compared with the predictions by the nonlinear analysis and the design codes. The confinement effect of lateral reinforcement increased the ductility of concrete, and the moment capacity of the column specimens increased with the ductility of concrete. The prediction by the nonlinear analysis gave good agreement with the test results. On the other hand, the ACI 318 neglecting lateral confinement effect underestimated the strength of the column specimens, and the Eurocode 4 using complete plastic capacity of steel section overestimated.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.6
• /
• pp.537-547
• /
• 2014

A steel modular unit structural system has been used increasingly for mid and high-rise buildings, since the building can be easily constructed by assembling the pre-made modular unit structures. For this structural system, each modular unit structures have to be properly connected to the foundation to transfer the axial force and the bending moment that are generated from external load to the ground. In this study, a new type of the embedded steel column-to-foundation connection was proposed, and its flexural behavior was evaluated through a series of experimental study. Five full scale specimens for the proposed connections were constructed and tested. The effect of the main parameters that affect the flexural behavior of the proposed connection, such as embedment length and shape of end plate, were studied. From the results, it was found that the flexural stiffness of the proposed connection was higher than that of the semi-rigid connection for all test specimens, and 200 mm of embedment length was proper for the given test specimens in this study.

• Magazine of the Korea Concrete Institute
• /
• v.10 no.6
• /
• pp.303-311
• /
• 1998

Ten reinforced concrete rigid frames and infilled shear wall frames were tested under both vertical and cyclic loadings. Experiments were carried out to evaluate the structural performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. under load reversals. All the specimens were modeledin one-third scale size. Based on the test results reported in this study, the follwing conclusions can be made. For the rigid frame type and the fully rigid babel type shear wall specimens, the hysteresis diagrams indicate that the degradations of their strength were developed slowly beyond maximum carrying capacity. It was shown that when the hoop reinforcement ratio became higher, the energy dissipation capacity became larger and the failure mode became ductile. The specimens designed by the less hoop reinforcement for the fully rigid babel type shear wall, were mainly failed due to diagonal crack in comparison with the specimens designed by the larger hoop reinforcement ratio. Maximum horizontal resisting moment capacity of speciment designed by the fully rigid babel shear wall were increased by 5.47~7.95 times in comparison with the rigid frame type.