• Title/Summary/Keyword: Brace

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An Experimental Study on Seismic Performance of Replaceable Steel Brace System with Sliding Slot (교체 가능한 강재 브레이스 시스템의 슬라이딩 슬롯 길이에 따른 내진성능에 관한 실험적 연구)

  • Kim Yoon Sung;Ro Kyong Min;Kim Min Sook;Lee Young Hak
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.35-42
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    • 2023
  • The purpose of this study is to experimentally analyze the seismic performance of column with RSB (Replaceable Steel Brace), a steel brace system with slot length as a variable. To evaluate the seismic performance of the RSB, three specimens were manufactured and subjected to cyclic loading tests. The length of the sliding slots were considered to be 5 mm and 10mm to enable the brace to resist the load from the initiation of flexural crack and shear crack. As a result of the test, the specimen reinforced with the RSB showed improved maximun load and effective stiffness, and energy dissipation capacity compared to the non-reinforced specimens. The specimens with 5mm sliding slot showed little difference in test result compared to the specimen with a 10mm sliding slot, indicating that the length of sliding slot has little influence on the effectiveness of RSB.

Structural Design and Construction of Mega Braced Frame System for Tall Buildings

  • Chung, Kwangryang;Yoo, Seounghoon
    • International Journal of High-Rise Buildings
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    • v.8 no.3
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    • pp.169-175
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    • 2019
  • Recently, two unique high rise buildings have been designed and constructed in Korea. The two buildings, which consist of mega braces and mega columns, are 70-story, 105-story high rise buildings. Through two external structural frame systems, it will be analyzed mechanical and structural characteristic mega column and mega brace system in this report. Particularly, the joint has been studied through the analytical method based on the load transfer mechanism at the point where a mega brace and mega column meets.

SKEW BRACE ENHANCEMENTS AND VIRTUAL LINKS

  • Melody Chang;Sam Nelson
    • Communications of the Korean Mathematical Society
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    • v.39 no.1
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    • pp.247-257
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    • 2024
  • We use the structure of skew braces to enhance the biquandle counting invariant for virtual knots and links for finite biquandles defined from skew braces. We introduce two new invariants: a single-variable polynomial using skew brace ideals and a two-variable polynomial using the skew brace group structures. We provide examples to show that the new invariants are not determined by the counting invariant and hence are proper enhancements.

Experimenal Study of Dynamic Characteristics of Brace-Typed Dampers using Vibration-resistant Rubbers (방진용 고무를 이용한 가새형 감쇠기의 진동 특성에 관한 실험 연구)

  • 민경원;김진구;조한묵;이성경;호경찬
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.381-385
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    • 1998
  • Vibration-resistant rubbers, whose elastic and shear behaviors are similar to viscoelastic materials, are used to make brace-typed dampers to reduce the building vibration. Experimental study is carried out to find the vibration characteristics of the dampers installed in the building model. The natural frequencies and modal damping ratios are obtained from the free vibration test and Fourier analysis. Analytical model of the modal strain energy method are used to find the viscoelastic characteristics of the brace-typed dampers from the experimental results. Finally shaking table test is performed to find the response behavior of the building model under earthquake loading. The present experimental study shows that the brace-typed dampers have the behavior of viscoelastic dampers, which increase the modal damping ratios and viscoelastic characteristics.

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Ellipsoidal bounds for static response of framed structures against interactive uncertainties

  • Kanno, Yoshihiro;Takewaki, Izuru
    • Interaction and multiscale mechanics
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    • v.1 no.1
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    • pp.103-121
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    • 2008
  • This paper presents an optimization-based method for computing a minimal bounding ellipsoid that contains the set of static responses of an uncertain braced frame. Based on a non-stochastic modeling of uncertainty, we assume that the parameters both of brace stiffnesses and external forces are uncertain but bounded. A brace member represents the sum of the stiffness of the actual brace and the contributions of some non-structural elements, and hence we assume that the axial stiffness of each brace is uncertain. By using the $\mathcal{S}$-lemma, we formulate a semidefinite programming (SDP) problem which provides an outer approximation of the minimal bounding ellipsoid. The minimum bounding ellipsoids are computed for a braced frame under several uncertain circumstances.

Seismic response analysis of RC frame core-tube building with self-centering braces

  • Xu, Long-He;Xiao, Shui-Jing;Lu, Xiao
    • Structural Monitoring and Maintenance
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    • v.5 no.2
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    • pp.189-204
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    • 2018
  • This paper examines the seismic responses of a reinforced concrete (RC) frame core-tube building with pre-pressed spring self-centering energy dissipation (PS-SCED) braces. The PS-SCED brace system consists of friction devices for energy dissipation, pre-pressed combination disc springs for self-centering and tube members as guiding elements. A constitutive model of self-centering flag-shaped hysteresis for PS-SCED brace is developed to better simulate the seismic responses of the RC frame core-tube building with PS-SCED braces, which is also verified by the tests of two braces under low cyclic reversed loading. Results indicate that the self-centering and energy dissipation capabilities are well predicted by the proposed constitutive model of the PS-SCED brace. The structure with PS-SCED braces presents similar peak story drift ratio, smaller peak acceleration, smaller base shear force and much smaller residual deformations as compared to the RC frame core-tube building with bucking-restrained braces (BRBs).

On the characteristics and seismic study of Hat Knee Bracing system, in steel structures

  • JafarRamaji, Issa;Mofid, Massood
    • Steel and Composite Structures
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    • v.13 no.1
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    • pp.1-13
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    • 2012
  • In this study, a new structural bracing system named 'Hat Knee Bracing' (HKB) is presented. In this structural system, a special form of diagonal braces, which is connected to the knee elements instead of beam-column joints, is investigated. The diagonal elements provide lateral stiffness during moderate earthquakes. However the knee elements, which is a fuse-like component, is designed to have one plastic joint in the knee elements for dissipation of the energy caused by strong earthquake. First, a suitable shape for brace and knee elements is proposed through elastic studying of the system and several practical parameters are established. Afterward, by developing applicable and highly accurate models in Drain-2DX, the inelastic behavior of the system is carefully considered. In addition, with inelastic study of the new bracing system and comparison with the prevalent Knee Bracing Frame system (KBF model) in nonlinear static and dynamic analysis, the seismic behavior of the new bracing system is reasonably evaluated.

AIM ORTHODONTIC CASE REPORT OF MILWAUKEE BRACE WEARER (Milwaukee brace 장착자(裝着者)의 교정치험례(橋正治驗例))

  • Nahm, Dong-Seok;Son, Woo-Sung
    • The korean journal of orthodontics
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    • v.14 no.1
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    • pp.39-45
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    • 1984
  • 10years and 8 months old patient, who had been wearing Milwaukee brace for 5 months, was treated by multibanded system without extract on. She complianed severe protrusion and interdental spacing of upper anterior teeth. Cephalometric analysis revealed short anterior facial height, infraclusion of the lower first molars and severe profrusion of upper and lower anterior teeth. During orthodontic treatment Milwaukee brace was replaced by TLSO, so the orthopedic force on the dentofacial region was eliminated. After 2 years and 3 months, she gained raised bite, increased interincisal angle, salient reduction in the protrusion of upper central incisals with agreeable overjet, complete obliteration of interdental spacing and reduction of protrusion of upper and lower lips.

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A Case Study of Six Sigma Project for Improving Productivity of the Brace Complement Center Pillar (Brace Complement Center Pillar의 생산성 향상을 위한 6시그마 프로젝트사례)

  • Lee, Min-Koo;Lee, Kwang-Ho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.29 no.1
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    • pp.9-17
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    • 2006
  • This paper considers a six sigma project for improving productivity of the brace complement center pillar. The project follows a disciplined process of fife phases: define, measure, analyze, improve, and control. A process map is used to identify process input and output variables. Eleven key process input variables are selected by using X&Y matrix and FMEA, and finally eight vital few input variables are selected from analyze phase. The optimum process conditions of the vital few input variables are jointly obtained by maximizing productivity of the brace complement center pillar using DOE and alternative selection method.