• Steel and Composite Structures
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• 제28권6호
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• pp.767-778
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• 2018

The purpose of this study is to investigate how a fully restrained bolted beam splice affects the connection behavior as a column-tree connection in steel special moment frames under cyclic loading when located within the plastic hinge zone. The impacts of this attachment in protected zone are observed by using nonlinear finite element analyses. This type of splice connection is designed as slip-critical connection and thereby, the possible effects of slippage of the bolts due to a possible loss of pretension in the bolts are also investigated. The 3D models with solid elements that have been developed includes three types of connections which are the connection having fully restrained beam splice located in the plastic hinge location, the connection having fully restrained beam splice located out of the plastic hinge and the connection without beam splice. All connection models satisfied the requirement for the special moment frame connections providing sufficient flexural resistance, determined at column face stated in AISC 341-16. In the connection model having fully restrained beam splice located in the plastic hinge, due to the pretension loss in the bolts, the friction force on the contact surfaces is exceeded, resulting in a relative slip. The reduction in the energy dissipation capacity of the connection is observed to be insignificant. The possibility of the crack occurrence around the bolt holes closest to the column face is found to be higher for the splice connection within the protected zone.

• 한국지반공학회논문집
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• 제32권12호
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• pp.45-57
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• 2016

IER은 굴착 중에 안정성을 증가시키기 위해서 전면지주에 배면지주를 기울어지게 설치하고 강결시킨 구조이다. IER은 배면지주가 억지말뚝의 역할을 함으로써 전면지주에 발생하는 수평변위를 억제하는 효과가 있고, 전면지주에 작용하는 토압을 분산 시켜 구조적으로 안정한 가시설 공법이다. 본 연구에서는 사질토 지반에서 수치해석과 실내모형실험을 통해 IER의 두부를 강결과 힌지로 조건을 다르게 연결하여 IER의 역학적 특성을 확인하였다. 수치해석 결과, 최대수평변위는 두부의 연결 방법이 강결일 때 힌지일 때의 88%가 발생하고 실내모형실험 결과, 수평변위는 두부 연결 방법이 강결일 때 힌지일 때의 단지 7%만 발생하는 것으로 분석되었다. 또한, 지반의 전단변형 해석 결과 토압은 두부의 연결 방법이 강결일 때 힌지일 때의 67%만 작용하는 것으로 분석되었다.

• Steel and Composite Structures
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• 제23권4호
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• pp.421-433
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• 2017

Experimental and numerical studies of a newly developed Reduced Beam Section (RBS) connection, called Tubular Web RBS connection (TW-RBS) have been recently conducted. This paper presents experimental and numerical results of extending the plastic hinge length on the beam flange to increase energy dissipation of a proposed version of the TW-RBS connection with two pipes, (TW-RBS(II)), made by replacing a part of flat web with two steel tubular web at the desirable location of the beam plastic hinge. Two deep-beam specimens with two pipes are prepared and tested under cyclic loads. Obtained results reveal that the TW-RBS(II) like its type I, increases story drift capacity up to 6% in deep beam much more than that stipulated by the current seismic codes. Based on test results, the proposed TW-RBS(II) helps to dissipate imposed energy up to 30% more than that of the TW-RBS(I) specimens at the same story drift and also reduces demands at the beam-to-column connection up to 30% by increasing plastic hinge length on the beam flange. The TW-RBS(II) specimens are finally simulated using finite element method showing good agreement with experimental results.

• 한국소음진동공학회논문집
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• 제16권2호
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• pp.132-140
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• 2006

This paper investigates the characteristics of dynamic responses of floating structures with connections under sea wave loads. Direct method using higher order boundary element method (HOBEM) and finite element method (FEM) is adopted for numerical analysis. A 500 m-long and 250-m width very large floating structure (VLFS) with four units are considered in numerical analysis. Hinge connection and spring connection with various strength are considered as connection types. Displacements and stresses of VLFS according to the connection types are compared considering wave period and heading angle reduction.

• 콘크리트학회논문집
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• 제23권3호
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• pp.303-310
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• 2011

복합 트러스교는 강재 박스 교량이 주류를 이루고 있는 우리나라 중지간 교량의 형식적 대안이 될 수 있는 구조 형식이다. 이러한 복합 트러스교의 핵심 기술은 강관과 콘크리트 슬래브를 연결하는 격점 구조이며 일본 등에서는 시공 회사별로 고유의 격점 구조를 개발하여 실험적 검증을 통해서 실교량에 적용해 오고 있다. 이 연구에서도 힌지형 격점 구조를 제안하고 이에 대한 정적인 구조 성능을 이미 검증한바 있으며 피로 실험을 통해 구조 상세를 개선하고 피로 성능을 검증하였다. 복합 트러스 거더에 대한 피로 실험 결과 정적인 구조 성능이 입증된 격점 구조라고 하더라도 매입된 연결판이 충분히 피로 파괴를 나타낼 수 있으며 이를 방지하지 하기 위한 구조 상세 개선 방안으로 perfobond 강재를 사용하는 방법과 강관에 원형 리브를 부착하는 방법을 제시하였다. 그리고 해석적 방법을 통해 강관에 원형 리브를 부착하는 방법이 격점부 강재 물량 증가시키지 않으면서도 피로 성능 개선에 효과적이라는 것을 입증하게 되었으며, 추가적인 격점 구조 피로 실험을 통해 피로 성능을 검증하였다. 따라서 이 연구에서 제안된 힌지형 격점 구조는 원형 리브를 부착하고 충분한 매입 깊이를 확보해 준다면 정적 구조 성능 뿐만 아니라 피로 성능도 확보되어 실제 복합 트러스 교량에서 유용하게 활용될 수 있을 것으로 사료된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.895-902
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• 2005

This paper investigates the characteristics of dynamic responses of floating structures with connections under sea wave loads. Direct method using higher order boundary element method and finite element method is adopted for numerical analysis. 500 m-long VLFS with four units are considered in numerical analysis. Hinge connection and spring connection with various strength are considered as connection types. Displacements and stresses of VLFS according to the connection types are compared considering wave period and heading angle.

• 콘크리트학회논문집
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• 제24권3호
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• pp.285-292
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• 2012

일반적으로 콘크리트 구조물은 보와 기둥이 서로 강결되어 있으며, 이러한 경우 강진에 의해 연결부에서 심각한 손상이 발생할 수 있다. 이를 저감시키면서 내진성능을 향상시키기 위한 다양한 연결 형태가 연구되어지고 있다. 그 한 예로 연결부에서의 회전을 허용하는 연결형식이 있으며 보나 기둥, 그리고 전단벽에 응용되고 있다. 이러한 회전형 구조요소들은 횡방향 거동시 비선형 힘-변위 관계를 나타내는데, 그 원인은 연결부의 회전으로 인한 접촉면의 깊이(contact depth)가 줄어듦과 동시에 요소의 각 단면에서의 응력이 비선형적으로 분포되는 탄성힌지 구간이 존재하기 때문이다. 이 연구에서는 축방향 하중(공칭강도의 5%와 10%)과 경계조건(양단구속 형식, 캔틸레버 형식), 세장비(L/d = 5, 7, 10) 등의 변수를 고려한 유한요소해석을 통해 회전형 기둥의 탄성힌지 구간 또는 길이를 분석하였다. 그 결과 이 세가지 변수는 탄성힌지길이 변화에는 직접적인 영향을 주지 않았으며 다만 접촉면의 깊이에 의해 지배됨을 알 수 있었다. 이 탄성힌지길이는 opening state부터 발생하기 시작하여 rocking point까지(pre-rocking 구간) 증가하였으나 그 이후(post-rocking 구간)에서는 일정한 값을 보였다. 탄성힌지길이에 대한 유한요소해석 결과를 이론적 예측식인 반무한모델(half space model)의 결과와 비교하였다.

• Steel and Composite Structures
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• 제31권3호
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• pp.319-327
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• 2019

This paper describes an experimental study of steel beam-column connections with or without expanded beam flanges with different geometries. The objectives of this study are to elucidate the cyclic behavior of these connections, identify the location of the plastic hinge zone, and provide useful test data for future numerical simulations. Five connection specimens are designed and tested under cyclic load. The test setup consists of a beam and a column connected together by a connection with or without expanded beam flanges. A constant axial force is applied to the column and a time varying point load is applied to the free end of the beam, inducing shear and moment in the connection. Because the only effect to be studied in the present work is the expanded beam flange, the sizes of the beam and column as well as the magnitude of the axial force in the column are kept constant. However, the length, width and shape of the expanded beam flanges are varied. The responses of these connections in terms of their hysteretic behavior, failure modes, stiffness degradation and strain variations are experimentally obtained and discussed. The test results show that while the influence of the expanded beam flanges on hysteretic behavior, stiffness degradation and energy dissipation capacity of the connection is relatively minor, the size of the expanded beam flanges does affect the location of the plastic hinge zone and strain variations in these beam-column joints. Furthermore, in terms of ductility, moment and rotational capacities, all five connections behave well. No weld fracture or premature failure occurs before the formation of a plastic hinge in the beam.

• 한국산업융합학회 논문집
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• 제27권4_2호
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• pp.833-840
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• 2024

According to recent data from the Korea Meteorological Administration(KMA), the frequency of typhoons around the Korea Peninsula is almost unchanged, but the intensity is on the rise due to climate change. A typhoon that has become so powerful can cause partial or complete damage to the traffic signal structures, limiting the operation of the vehicle and causing traffic congestion. If the traffic signal structure fails to function properly due to the influence of the typhoon, not only the v ehicle operation will be disrupted, but also direct damage to the traffic signal structure will occur. In addition, if the social overhead cost of traffic congestion is included, the recovery cost caused by the typhoon will increase to an extent that it is difficult to estimate. Therefore, in this study, a wind tunnel experiment was performed by producing a wind tunnel model of an existing fixed traffic signal structure and a traffic signal structure in which signs and traffic lights are hinged. Also, The fixed and hinge structures were modeled as 3D finite elements, and wind-resistant analysis was performed by wind speed, and, wind-resistant safety of traffic signal structures were analyzed and examined through wind-resistant analyses. From the comparative analysis of the results of experiment and FE analysis, it was known that the stress reduction rate of the hinge connection structure was at least 30% compared to that of the fixed connection structure from the results of the wind tunnel experiment and FE analysis. And As a result of finite element analysis for the maximum design wind speed of 50m/s, it was found that the maximum stress generated in the existing structure exceeded all the yield stress, but the maximum stress of the hinge connection structure was within the yield stress. Finally The hinge connection structure showed a relatively large stress reduction rate as the wind speed increased and the length of the lateral beam was shorter at the same wind speed.

• Steel and Composite Structures
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• 제26권1호
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• pp.31-44
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• 2018

This paper reports a novel steel beam-to-column connection suitable for use in the weak axis of I-section column. Monotonic and cyclic loading experimental investigations and numerical analysis of the proposed weak-axis connection were conducted, and the calculation procedure of the beam-column relative rotation angle and plastic rotation angle was developed and described in details. A comparative analysis of mechanical property and steel consumption were employed for the proposed I-section column weak-axis connection and box-section column bending connection. The result showed that no signs of fracturing were observed and the plastic hinge formed reliably in the beam section away from the skin plate under the beam end monotonic loading, and the plastic hinge formed much closer to the skin plate under the beam end cyclic loading. The fracture of welds between diaphragm and skin plate would cause an unstable hysteretic response under the column top horizontal cyclic loading. The proposed weak-axis connection system could not only simplify the design calculation progress when I-section column is adopted in frame structural design but also effectively satisfy the requirements of 'strong joint and weak member', as well as lower steel consumption.