• Steel and Composite Structures
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• 제17권1호
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• pp.47-67
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• 2014

Due to thermal expansion, the structural behaviour of beams in steel structures subjected to temperature increase will be affected. This may result in the failure of the structural members or connection due to extra internal force in the beam induced by the thermal increase. A method to release some of the thermally generated internal force in the members is to allow for some movements at the end supports of the member. This can be achieved by making the plane of the end-plate of the connection slanted instead of vertical as in conventional design. The present paper discusses the mechanical behaviour of beams with bolted slant end-plate connection under symmetrical gravity loads, subjected to temperature increase. Analyses have been carried out to investigate the reduction in internal force with various angles of slanting, friction factor at the surface of the connection, and allowable temperature increase in the beam. The main conclusion is that higher thermal increase is tolerable when slanting connection is used, which means the risk of failure of structures can be reduced.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.615-622
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• 2006

As construction technique and design are developing, the bridge tend to be longer, and also the type of bridge is verity. Steel and concrete combination improve the mechanics characteristic and economical efficient which Hybrid Structure divide Mixed Structure with Composite Structure. The connected section of the Mixed Structure should integrate steel and concrete that should show the same behavior as well, And also this connection needs big interna1 force and stiffness because it used to be a most dangerous section. This study carry out a nonlinear analysis technique with slip, check out each different type of section force's transfer mechanism on the connection. And this analysis was carried out using parameter that are front plate thickness, connection length, filled concrete strength and so on. We confirmed the profitable type of connection is front backward type. The biggest stiffness and certain stress transmission are showed at the ratio 0.075 between total length and connection length, and also most economical front plate thickness is judged when it set three times thicker than flange.

• 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.

• Industrial Engineering and Management Systems
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• 제8권1호
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• pp.66-71
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• 2009

This study proposes a new framework for designing disassembly methods. In recent years, environmental problems have become global issues. Recycling of used products or resources is recognized as a matter of significance since it may help reduce the risk of exhausting natural resources. Considering possible exhaustion of limited natural resources in the near future, reuse of products would gain more environmental significance. As yet, it relies hugely on manual disassembly, which labor cost places burden on the total recycling cost. The purpose of this study is to propose a methodology designing for manual disassembly works, and a creation method of a jig. By focusing on parts' connection and attachment relationship, parts are categorized in 5 categories (parent part, joint key part, attaching key part, child part, and independent part) according to the features that parts possess, and 3 kinds of connection relationships (parent part-joint key part connection, parent part-independent part connection and child part-child part connection) are clarified. Connection relationship and attachment relationship charts have also been created, and utilizing them, disassembly orders are settled, and a disassembly jig is devised. The proposed methodology is also applied to a real product and its work time is improved 42% form 31 to 13 seconds.

• Steel and Composite Structures
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• 제31권6호
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• pp.617-628
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• 2019

As an extremely destructive accident, progressive collapse is defined as the spread of an initial local failure from element to element, resulting eventually in the collapse of an entire structure or disproportionately large of it. To prevent the occurrence of it and evaluate the ability of structure resisting progressive collapse, the nonlinear static procedure is usually adopted in the whole structure design process, which considered dynamic effect by utilizing Dynamic Increase Factor (DIF). In current researches, the determining of DIF is performed in full-rigid frame, however, the performance of beam-column connection in the majority of existing frame structures is not full-rigid. In this study, based on the component method proposed by EC3 guideline, the expression of extended endplate connection performance is further derived, and the connection performance is taken into consideration when evaluated the performance of structure resisting progressive collapse by applying the revised plastic P-M hinge. The DIF for structures with extended endplate beam-column connection have been determined and compared with the DIF permitted in current GSA guideline, the necessity of considering connection stiffness in determining the DIF have been proved.

• Steel and Composite Structures
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• 제42권1호
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• pp.49-57
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• 2022

This paper presents a study on the behavior of a bolted T-stub to square tube connection using Thread-fixed One-side Bolts (TOBs) through tests and numerical simulations. It outlines a research work of four connections with focus on the failure modes and strengths of the connection under tensile load. It was observed that the thread anchor failure caused by shear failure of hole threads controlled the final failure of the connection in the tests. Meanwhile, the out-of-plane deformation of tube wall resulted in the contact separation between hole threads and bolt threads, which in turn reduced the shear strength of hole threads. Finite element models (FEMs) allowing for the configuration details of the TOBs fixed connection are then developed and compared with the test results. Subsequently, the failure mechanism of hole threads and stress distribution of each component are analyzed based on FEM results. It was concluded that the ultimate strength of connection was not only concerned with the shear strength of hole threads, but also was influenced by the plastic out-of-plane deformation of tube wall. These studies lay a foundation for the establishment of suitable design methods of this type of connection.

• Structural Engineering and Mechanics
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• 제88권5호
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• pp.501-519
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• 2023

This paper introduces a new hybrid structural connection joint that combines shear walls with section steel beams, fundamentally resolving the construction complexity issue of requiring pre-embedded connectors in the connection between shear walls and steel beams. Initially, a quasi-static loading scheme with load-deformation dual control was employed to conduct low-cycle repeated loading experiments on five new connection joints. Data was acquired using displacement and strain gauges to compare the energy dissipation coefficients of each specimen. The destruction process of the new connection joints was meticulously observed and recorded, delineating it into three stages. Hysteresis curves and skeleton curves of the joint specimens were plotted based on experimental results, summarizing the energy dissipation performance of the joints. It's noteworthy that the addition of shear walls led to an approximate 17% increase in the energy dissipation coefficient. The energy dissipation coefficients of dog-bone-shaped connection joints with shear walls and cover plates reached 2.043 and 2.059, respectively, exhibiting the most comprehensive hysteresis curves. Additionally, the impact of laminated steel plates covering composite concrete floors on the stiffness of semi-rigid joint ends under excessive stretching should not be disregarded. A comparison with finite element analysis results yielded an error of merely 2.2%, offering substantial evidence for the wide-ranging application prospects of this innovative joint in seismic performance.

• Structural Engineering and Mechanics
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• 제89권2호
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• pp.155-170
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• 2024

Several types of column-beam connections are used in the design of steel structures. This situation causes different cross-section effects and, therefore, different displacements and deformations. In other words, connection elements such as welds, bolts, continuity plates, end plates, and stiffness plates used in steel column-beam connections directly affect the section effects. This matter reveals the necessity of knowing the steel column-beam connection behaviours. In this article, behaviours of bolted column-beam connection with end plate widely used in steel structures are investigated comparatively the effects of the stiffness plates added to the beam body, the change in the end plate thickness and bolt diameter. The results obtained reveal that the moment and force carrying capacity of the said connection increases with the increase in the end plate thickness and bolt diameter. In contrast, it causes the other elements to deform and lose their capacity. This matter shows that optimum dimensions are very important in steel column-beam connections. In addition, it has been seen that adding a stiffness plate to the beam body part positively contributes to the connection's moment-carrying capacity.

• 한국지반신소재학회논문집
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• 제8권3호
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• pp.45-52
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• 2009

최근 국내에서는 시공성 및 경제성이 우수하고, 수려한 경관을 연출할 수 있는 보강토옹벽의 적용이 급증하고 있는 추세이다. 일반적으로 블록식 보강토옹벽 시공시 전면블록과 보강재 사이의 연결은 블록에 미리 형성시킨 돌기(전단키형 방식) 또는 플라스틱 핀(핀형 방식)을 이용하여 보강재를 블록에 정착시키는 방식으로 이루어지고 있다. 그러나 이와 같은 연결방식은 시공중 보강재에 부분적인 손상의 원인이 되며, 이로 인해 보강토옹벽의 안정성에 문제를 야기시킬 수 있다. 따라서 본 연구에서는 기존 연결방식의 문제점을 해결하고자, 안정성을 보다 높이고 경제성은 기존 방식과 유사한 I형 연결장치를 이용한 전면블록/지오그리드 보강재의 연결방법을 개발하였으며, 현장 적용을 위하여 연결강도 특성을 평가하였다.