• Steel and Composite Structures
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• 제1권3호
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• pp.269-282
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• 2001

In this paper the results of an experimental program devoted to the assessment of the cyclic behaviour of full scale, European type, beam-column subassemblages with welded connections are presented. Six tests (five cyclic and one monotonic) have been carried out on three different series of specimens, encompassing a total of eighteen tests. The three specimen series have been designed with the aim of defining the effect of the column size on the connection behaviour, under different applied loading histories. The tests have evidenced the effect of the column size and panel zone design and of the applied loading history on the cyclic behaviour and failure modes of the connections.

• Structural Engineering and Mechanics
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• 제54권1호
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• pp.35-54
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• 2015

The performance of a newly generated steel connection known as SidePlateTM moment connection for seismic loading and progressive collapse phenomenon has been investigated in this paper. The seismic evaluation portion of the study included a thorough study on of interstory drift angles and flexural strengths based on 2010 AISC Seismic Provisions while the acceptance criteria provided in UFC 4-023-03 guideline to resist progressive collapse must be satisfied by the rotational capacity of the connections. The results showed that the SidePlate moment connection was capable of attaining adequate rotational capacity and developing full inelastic capacity of the connecting beam. Moreover, the proposed connection demonstrated an exceptional performance for keeping away the plastic hinges from the connection and exceeding interstory drift angle of 0.06 rad with no fracture developments in beam flange groove-welded joints. The test results indicated that this type of connection had strength, stiffness and ductility to be categorized as a rigid, full-strength and ductile connection.

• Steel and Composite Structures
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• 제35권3호
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• pp.353-370
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• 2020

This paper describes a new type of replaceable fuse for moment resisting frames. Column-tree connections with beam splice connections are frequently preferred in the moment resisting frames since they eliminate field welding and provide good quality. In the column-tree connections, a part of the beam is welded to the column in the shop and the rest of the beam is bolted with the splice connection in the field. In this study, a replaceable reduced beam section (R-RBS) connection is proposed in order to eliminate welding process and facilitate assembly at the site. In the proposed R-RBS connection, one end is connected by a beam splice connection to the beam and the other end is connected by a bolted end-plate connection to the column. More importantly is that the proposed R-RBS connection allows the replacement of the damaged R-RBS easily right after an earthquake. Pursuant to this goal, experimental and numerical studies have been undertaken to investigate the performance of the R-RBS connection. An experimental study on the RBS connection was used to substantiate the numerical model using ABAQUS, a commercially available finite element software. Additionally, five different finite element models were developed to conduct a parametric study. The results of the analysis were compared in terms of the moment and energy absorption capacities, PEEQ, rupture and tri-axiality indexes. The design process as well as the optimum dimensions of the R-RBS connections are presented. It was also demonstrated that the proposed R-RBS connection satisfies AISC criteria based on the nonlinear finite element analysis results.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.473-478
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• 2003

The purpose of this study is to model the seismic behavior of Welded Unreinforced Flange and Bolted (WUF-B) connections with post-Northridge details and evaluate the system performance of the builidings with WUF-B connections. For this purpose, based on test results, mathematical model of the connections were developed and compared with test results. This connection model take into account both panel zone deformation and connection fractures. Then, SAC Phase II 3 and 9-story buildings were modeled using the connection model developed in this study. From nonlinear static pushover analysis of the buildings, maximum strength, maximum roof drift, and so forth are investigated for the buildings with post-Northridge details. Analysis results were compared with those of buildings with pre-Northridge details and ductile connections with no fractures.

• 한국소음진동공학회논문집
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• 제13권12호
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• pp.930-937
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• 2003

This research deals with how to select connection positions of two substructures to be synthesized. The goal of this research is to find optimal connection positions in order to maximize the fundamental natural frequency of the synthesized structure. The natural frequencies of a connected structure are obtained by modal-force equations. Optimal connection positions can be selected through optimization process. In the optimization process, the natural frequencies of a connected structure are set to object function value and connection positions become design variables. The method described above is applied to synthesis problems of plates, which is initially conducted for FE models and verified through experiments. Especially in experiments. FRF(frequency response function) s are obtained by means of the Modal Testing technique to be used in modal-force equations for synthesizing. Once the substructures are synthesized. the Modal Testing technique is again applied to spot-welded structure using the result from the optimization procedure. It is found that the fundamental natural frequency of the synthesized structure with the optimized result gives higher value than those with the initially given connection positions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.65-71
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• 2003

This research deals with how to select connection positions of two substructures to be synthesized. The goal of this research is to find optimal connection positions in order to maximize the fundamental natural frequency of the synthesized structure. The natural frequencies of a connected structure are obtained by modal-force equations. Optimal connection positions can be selected through optimization process. In the optimization process, the natural frequencies of a connected structure are set to object function value and connection positions become design variables. The method described above is applied to synthesis problems of plates, which is initially conducted for FE models and verified through experiments. Especially in experiments, FRE(frequency Response function)s are obtained by means of the Modal Testing technique to be used in modal-force equations for synthesizing. Once the substructures are synthesized, the Modal Testing technique is again applied to spot-welded structure using the result from the optimization procedure. It is found that the fundamental natural frequency of the synthesized structure with the optimized result gives higher value than those with the initially given connection positions.

• 한국강구조학회 논문집
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• 제29권1호
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• pp.25-36
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• 2017

1994년 노스리지 지진 당시 발생한 용접모멘트 접합부의 취성파괴는 주로 보 하부 플랜지에서 발생하였다. 특히 국내 기존 용접철골모멘트 접합부의 경우 과다한 전단스터드 배치에 따른 의도치 않은 합성작용로 인해 지진 내습 시 보 하부 플랜지의 취성파단이 더욱 우려되는 실정이다. 본 논문에서는 합성효과로 인한 접합부 성능저하를 개선하기 위한 목적으로 중량전단탭/수평헌치/삼각헌치로 보강된 접합부 및 RBS가 도입된 접합부에 대한 실험을 실시하였다. 통상 기존 접합부 상부 플랜지의 수정이 불가하다는 점을 고려하여, 본 연구에서는 보 하부 플랜지에만 수평/삼각헌치를 보강하거나 RBS를 도입하여 이 때의 내진성능을 평가하였다. 실물대 실험 결과 수평/삼각헌치 혹은 중량전단탭으로 보강한 실험체는 모두 합성작용으로 인한 부작용을 극복하고 특수모멘트접합부가 요구하는 수준 이상의 소성회전각 5%이상을 발현함을 확인하였다. 또한 SRC 기둥에 RBS를 도입할 경우 접합부에 소요되는 변형의 대부분을 RBS측에서 일어나도록 유도함으로써 SRC기둥에 발생하는 손상을 방지하는 효과가 있음을 규명하였다. 이 중 중량전단탭 보강에 따른 접합부의 거동을 분석하기 위하여 추가의 수치해석 연구를 실시하였으며, 제시한 각각의 보강안에 대한 권장상세를 제시하였다.

• 대한토목학회논문집
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• 제6권3호
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• pp.75-86
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• 1986

철도궤조(軌條) 용접연결부(鎔接連結部)는 용접(鎔接)에 의한 저인성(低靭性), 잔류응력(殘溜應力), 용접변형등(鎔接變形等)의 효과로 피로균열성장거동(疲勞龜裂成長擧動)의 복잡성을 나타낸다. 또한 철도궤조(軌條)의 장대화(長大化)로 용접연결(鎔接連結)이 불가피하며 용접연결부(鎔接連結部)에서는 피로파괴(疲勞破壞)가 빈번히 발생(發生)하고 있다. 이에 본(本) 연구(硏究)는 소재부(素材部), 가스압접부(壓接部), 테르밋트용접부(鎔接部)에 대하여 피로실험(疲勞實驗)을 행(行)하여 S-N 선도작성(線圖作成)의 기본적인 자료를 제시코져 하였다. 그 결과(結果), 소재부(素材部)가 용접부(鎔接部)보다, 또 가스압접부(壓接部)가 테르밋트용접부(鎔接部)보다 피로균열성장(疲勞龜裂成長)에 대한 저항성(抵抗性)이 좋으며, 이와같은 용접부(鎔接部)와 고강도(高强度)의 궤조강(軌條鋼)은 종래의 재료역학적(材料力學的)인 방법(方法)만으로 파괴(破壞)를 제어하는 것은 매우 위험하다는 것을 알 수 있었다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.808-813
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• 2009

Top-down method is widely used for urban area construction for its advantages in reducing environmental problems such as dust and noise, and saving construction cost depending on given conditions of a construction site. Because the excavation and construction of super- and sub-structures of the building have to be proceeded simultaneously, a column has to be embedded prior to excavation. This column is called a pillar column or pre-founded column. Usually a wide flange section is used for these columns. To place the columns, usually the diameter of casing holes needs to be larger than the section of the wide flange itself in order to accommodate a couple of tremie pipes for pouring concrete. In this paper, a newly developed method of using circular pipe as an alternative to the existing wide flange section is discussed. The crucial part of the new method is to develop a connection between the circular column and concrete flat slabs. For shear force transfer from concrete slab to the concrete filled tube (CFT) column, shear jackets with studs and shear bands are proposed. The studs are welded on the jackets at shop and placed around the circular column on site. The shear bands are welded on the outer side of the CFT at shop and inserted into ground with the CFT. Test results and application of the method to a construction site are also provided in this paper.

• Steel and Composite Structures
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• 제19권4호
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• pp.877-895
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• 2015

Connections to circular hollow steel sections (CHS) are considered one of the most complex and time consuming connections in steel construction. Such connections are usually composed of gusset plates welded to the outside of the steel tube or penetrating the steel tube. Design guides, accounting for the effect of connection configuration on the strength of the connection, are not present. This study aims to investigate, through experimental testing and a parametric study, the influence of connection configuration on the strength of one sided branch plate-to-CHS members. A notable effect was observed on the behavior of the connections due to its detailing changes with respect to capacity, failure mode, ductility, and stress distribution. A parametric study is performed using the calibrated analytical model to include a wider range of parameters. The study involves 26 numerical analyses of finite element models including parameters of the diameter-to-thickness (D/t) ratio, length of gusset plate, and connection configuration. Accordingly, a modification to the formulas provided by the current design recommendations was suggested to include connection configuration effects for the one sided branch plate-to-CHS members.