• Title/Summary/Keyword: pinned connections

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Classification system for figid and semi-rigid connection (강·반강 철골 접합부의 분류체계에 관한 연구)

  • Jang, Mee;Lee, Sang Sup;Mun, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.351-361
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    • 2001
  • The connections are classified as rigid, semi+rigid, or pinned. There are two classification systems, EC3 adn Bjorhovede et al., representatively. The EC3 boundary between rigid and semi-rigid connections is in on the whole restrictive in term of the stiffness as well as the moment capacity of connections. The boundary specified by Bjorhovede et al. may not be sufficient to assure the behavior of rigid frames in some cases. In this study, it is proposed the new classification system for steel connection that depends on the reduction factor(R) of critical buckling load for unbraced semi-rigid frame expressed by the stiffness ratio($\rho$) of beam to column and the stiffness ratio(k) of connection to beam. Finally, it is examined by experimental data that new classification criteria provides a practical boundary compared wit hteh existing classifications.

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Design and Applications of Buckling-Restrained Braces

  • Watanabe, Atsushi
    • International Journal of High-Rise Buildings
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    • v.7 no.3
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    • pp.215-221
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    • 2018
  • Buckling-Restrained Braces (BRBs) have been widely applied to tall buildings in seismic areas in the world. In this paper the author summarizes representative types of BRB compositions and shows two cases of special applications of BRBs. In the first case, BRB diagonals for tall building were used to provide stable cyclic nonlinear hysteresis and also used to limit forces generated at columns, connections and walls. The top outriggers are pre-loaded by jacks to resolve long-term differential shortenings between the concrete core wall and concrete-filled steel box columns. The second case is the retrofit work for a communication tower by replacing the insufficiently strong members with BRBs in Japan.

Dynamic Analysis of Superstructures on Very Large Floating Structure with Semi-Rigid Connections (반강접 접합부를 적용한 초대형 부유식 구조물 상부구조체에 대한 동적해석)

  • Song Hwa-Cheol;Kim Woo-Nyon
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.389-394
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    • 2005
  • The additional moment occurs because the superstructures of VLFS are influenced by wave loads instead of earthquake loads. In order to reduce the additional moment, this study used the semi-rigid connections which lie between fully rigid and pinned. If the semi-rigid connections are used for superstructures of VLFS, the moment of beams can be reduced and more economical construction will be possible. This study aims to show the effect of wave loads on structure and the efficiency of the semi-rigid connections due to wave loads by analyzing the time history responses. The dynamic behaviors of the rigid frame are compared with those of the semi-rigid frame considering of static loads, wave loads and combination loads for a four-bay, three-story frames. The semi-rigid connection type is a steel tubular column with square external-diaphragm connections and the time history analysis is used for the dynamic responses. The additional moment responses due to wave loads increase $33\%$ in the rigid frame, $26\%$ in the semi-rigid frame with the spring model.

Experimental and numerical evaluation of an innovative diamond-scheme bracing system equipped with a yielding damper

  • Pachideh, Ghasem;Gholhaki, Majid;Kafi, Mohammadali
    • Steel and Composite Structures
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    • v.36 no.2
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    • pp.197-211
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    • 2020
  • Application of the steel ring as a type of seismic fuse has been one of the efforts made by researchers in recent years aiming to enhance the ductility of the bracing systems which in turn, possesses various advantages and disadvantages. Accordingly, to alleviate these disadvantages, an innovative bracing system with a diamond scheme equipped with a steel ring is introduced in this paper. In this system, the braces and yielding circular damper act in parallel whose main functionality is to increase ductility, energy absorption and mitigate drawbacks of the existing bracing systems, in which the braces and yielding circular damper act in parallel. To conduct the experimental tests, specimens with three types of rigid, semi-rigid and pinned connections were built and subjected to cyclic loading so that their performance could be analyzed. Promisingly, the results indicate both great applicability and efficiency of the proposed system in energy absorption and ductility. Moreover, it was concluded that as the braces and damper are in parallel, the use of a steel ring with smaller size and thickness would result in higher energy absorption and load-resisting capacity when compared to the other existing systems. Finally, to assess the potential of numerically modeling the proposed system, its finite element model was simulated by ABAQUS software and observed that there is a great agreement between the numerical and experimental results.

Evaluation on the Behavioral Characteristics of Plastic Greenhouse by Full-scale Testing and Finite Element Analysis (재하시험과 유한요소해석에 의한 플라스틱 필름 온실의 거동특성 분석)

  • Ryu, Hee Ryong;Lee, Eung Ho;Cho, Myeong Whan;Yu, In Ho;Kim, Young Chul
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.459-465
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    • 2012
  • This study analyzed the effect of semi-rigid rafter-purlin cross-linking connection and driven steel pipe base on the static behavior of plastic greenhouse (PG). To promote the time and cost efficiency of the assembly process, each cross-linking connections of space arch type grid that consists of rafter and purlin is linked with steel-wire buckles, and each end of the rafters was driven directly to the ground to support the PG structure. However, in the design process, cross-linking connections and bases are idealized by being categorized as fully rigid or frictionless pinned, which does not appropriately reflect actual conditions. This study takes a full-scale loading test of PG and analyzes the effect of member cross-linking connections and driven steel pipe base on the behavior of a structure. The analysis provided a basis for determining the rigidity factor of member cross-linking nodes needed for finite element analysis, and the reliability of the result regarding the static behavior of PG.

Analysis Model for Approximate Evaluation of Stiffness for Semi-Rigid Connection of Wooden Structures (목조 구조물 접합부의 강성에 대한 근사평가를 위한 해석모델)

  • Cho, So-Hoon;Lee, Heon-Woo;Park, Moon-Jae;Kim, Taejin;Kim, Jong-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.1
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    • pp.93-100
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    • 2015
  • Modern wooden structures usually are connected with steel fastener type connectors. And joints using multiple connectors in wooden structures will form semi-rigid connection. If connection in wooden structure would be designed to be pinned joint, the underestimate for loads transmitted through connection, would result in the deficient capacity of resistance in connection. And if joints in wooden structures would be assumed to be fully-rigid joint, amount of fasteners needed at the connection could be excessively increased. It will give a bad effect in the view of beauty, constructability and economy. Estimate for the reasonable stiffness of connection might be essential in design of reasonable connection in wooden structure. This paper will suggest analysis modelling technique that can represent approximate stiffness of connections using a common analysis program for double shear connection in order to give help in performing easily the design of wooden structure. It is verified that the suggested approximate analysis modelling technique could represent the behavior in connection by comparing the analysis results with test results for tensile, bending moment.