研究者データベース

研究者情報

マスター

アカウント(マスター)

  • 氏名

    松井 良太(マツイ リヨウタ), マツイ リヨウタ

所属(マスター)

  • 工学研究院 建築都市部門 先端空間性能

所属(マスター)

  • 工学研究院 建築都市部門 先端空間性能

独自項目

syllabus

  • 2021, 建築振動工学特論, Dynamics of Building Structures, 修士課程, 工学院, 振動、構造解析、地震応答、数値解析、1自由度系、多自由度系
  • 2021, 建築振動工学特論, Dynamics of Building Structures, 博士後期課程, 工学院, 振動、構造解析、地震応答、数値解析、1自由度系、多自由度系
  • 2021, 応用数学Ⅰ, Applied Mathematics I, 学士課程, 工学部, 常微分方程式 フーリエ解析 フーリエ変換
  • 2021, 建築構造動力学, Structural Dynamics, 学士課程, 工学部, 動力学,耐震工学,強震動,離散系,耐震基準
  • 2021, 構造解析Ⅰ, Structural Analysis I, 学士課程, 工学部, 動力学,耐震工学,強震動,離散系,耐震基準
  • 2021, 応用数学演習Ⅰ, Exercise in Applied Mathematics I, 学士課程, 工学部, 常微分方程式  フーリエ解析  偏微分方程式

researchmap

プロフィール情報

学位

  • 博士(工学)(東京工業大学)

プロフィール情報

  • 松井, マツイ
  • 良太, リョウタ
  • ID各種

    201601008716890575

業績リスト

研究キーワード

  • 構造実験   数値解析   鋼構造   建築構造   

研究分野

  • 社会基盤(土木・建築・防災) / 建築構造、材料 / 鋼構造

経歴

  • 2018年10月 - 現在 北海道大学 工学研究院 建築都市空間デザイン部門 空間防災分野 准教授
  • 2016年04月 - 2018年09月 東京工業大学 環境・社会理工学院 建築学系 助教
  • 2011年04月 - 2016年03月 東京工業大学 理工学研究科建築学専攻 助教

学歴

  • 2008年03月 - 2011年03月   東京工業大学   理工学研究科   建築学専攻 博士課程
  • 2006年04月 - 2008年03月   東京工業大学   理工学研究科   建築学専攻 修士課程
  • 2002年04月 - 2006年03月   東京工業大学   工学部   建築学科

委員歴

  • 2020年04月 - 現在   日本鋼構造協会   鋼構造論文集編集委員会
  • 2019年04月 - 現在   日本建築学会   軽鋼構造設計施工指針改定小委員会
  • 2015年07月 - 現在   日本鋼構造協会   ステンレス技術・標準委員会、ステンレス構造普及活動のための教育資料検討TG
  • 2014年06月 - 現在   日本建築学会   鋼構造座屈小委員会
  • 2020年04月   日本鋼構造協会   論文集小委員会
  • 2015年08月 - 2020年03月   日本建築学会   鋼構造関連規準・指針の英文化小委員会
  • 2017年07月 - 2019年03月   日本防災協会   システムトラスによる立体屋根構造の耐震性の確保に向けた検討委員会

受賞

  • 2019年05月 日本建築学会 日本建築学会著作賞
     Buckling-Restrained Braces and Applications 
    受賞者: 竹内徹;和田章;松井良太;Sitler Ben;林保均;Sutcu Fatih;坂田弘安;曲哲
  • 2013年08月 日本建築学会 日本建築学会奨励賞
     
    受賞者: 松井 良太
  • 2012年02月 東京工業大学 手島精一記念研究賞 博士論文賞
     
    受賞者: 松井 良太
  • 2011年11月 日本鋼構造協会 第19回鋼構造シンポジウム 優秀発表賞
     
    受賞者: 松井 良太
  • 2011年03月 都市地震工学センター 優秀発表賞
     
    受賞者: 松井 良太

論文

  • 寺澤友貴, 石橋洋二, 田中陽樹, 横山亮, 水野紘貴, 竹内徹
    日本建築学会構造系論文集 Vol. 87 No. 802 2022年12月10日
  • Yuta FUKE, Taichiro OKAZAKI, Ryota MATSUI
    AIJ Journal of Technology and Design 28 70 1236 - 1241 2022年10月20日
  • Ryota Matsui, Zhang Yiyue, Taichiro Okazaki, Toru Takeuchi
    Lecture Notes in Civil Engineering 216 - 223 2022年 [査読有り]
  • Ryota Matsui, Koichi Koizumi, Pao-Chun Lin, Masanobu Iwanaga, An-Chien Wu, Toru Takeuchi, Keh-Chuyan Tsai
    Journal of Structural Engineering 147 7 2021年07月 [査読有り]
  • Ben Sitler, Toru Takeuchi, Ryota Matsui, Masao Terashima, Yuki Terazawa
    Engineering Structures 213 110482 - 110482 2020年06月 [査読有り]
     
    © 2020 The Authors While buckling-restrained braces offer excellent energy dissipation characteristics, their low post-yield stiffness may result in large residual drifts and interstory drift concentration when used in simply supported frames. This paper introduces a new multistage buckling-restrained brace to help mitigate these design challenges. The proposed device features two low yield point (LYP) cores with LY225 and short yield lengths, and one high yield point (HYP) core with SA440B and a longer yield length. In a design level event, the LYP cores dissipate energy, while the parallel HYP core provides an elastic restoring force. At large drifts, the HYP core yields and the device acts similar to a high-capacity, ductile, conventional BRB. A 384 kN specimen was tested at up to 1.5% strain and the individual core contributions recorded using strain gauges attached to the elastic core segments inside the restrainer. The multistage response matched the predicted trilinear backbone, achieving 10 to 20% equivalent damping prior to yielding the HYP core, and a fatigue capacity exceeding three times the AISC 341-16 acceptance criteria. Interaction between the decoupled cores was studied using a 3D finite element model, indicating that minor detailing changes could further improve performance.
  • Fatih Sutcu, Ahmet Bal, Kazuhiro Fujishita, Ryota Matsui, Oguz C. Celik, Toru Takeuchi
    Bulletin of Earthquake Engineering 18 5 2389 - 2410 2020年03月01日 
    © 2020, Springer Nature B.V. Existing reinforced concrete (RC) buildings designed according to outdated codes may lack sufficient strength, stiffness or ductility to meet the seismic performance criteria of current codes. To enhance the system stiffness and re-centering capability, an elastically designed supplementary steel frame (SF) is installed in parallel with the BRBs. Near full-scale cyclic tests are conducted on such retrofit schemes for performance evaluation. The retrofitted specimens showed stable hysteretic behavior up to the retrofit target story drift of 1/150 as proposed in the Japanese seismic regulations. Tests demonstrate that the proposed system is feasible and increases both strength, ductility, and damping to an adequate seismic performance level while the elastic steel frame is effective in providing post-yield stiffness and re-centering capability even when the RC frame is subjected to moderate inelasticity. Special emphasis is placed on the composite behavior of RC members and SF. A simplified composite interaction model is proposed and results from the developed model show good agreement with the experimental data. Ductility demands are shown to concentrate in the BRBs as per the design intent.
  • 福富将, 岡崎太一郎, 松井良太, 麻里哲広
    日本建築学会構造系論文集 85 778 1555 - 1563 2020年 [査読有り]
  • Pao-Chun Lin, Toru Takeuchi, Ryota Matsui
    Engineering Structures 194 441 - 457 2019年09月 [査読有り]
     
    © 2019 The outrigger system is an effective solution in mitigating seismic responses of core-tube-type tall buildings by mobilizing the axial stiffness of the perimeter columns. The concept of damped-outrigger has been proposed which introduces dampers in the outrigger system to dissipate seismic energy. This study investigates the seismic behavior of a damped-outrigger system incorporating buckling-restrained brace (BRB-outrigger). The outrigger effect combined with the energy dissipation mechanism of the buckling-restrained brace (BRB) effectively reduce the seismic response of the building. This study proposes the methods to evaluate the inelastic seismic response of structures with multiple damped-outriggers based on a spectral analysis (SA) procedure. For the structure with BRB-outriggers, the optimal outrigger elevations, and the relationships between the axial stiffness of the BRB, the axial stiffness of the perimeter column, and the flexural rigidity of the core structure in order to minimize the seismic response are the primary research objectives of this study. Analytical models with building heights of 64 m, 128 m, 256 m, and 384 m are used to perform the SA and the nonlinear response history analysis. This study concludes with a design recommendation for preliminary design purposes.
  • 松崎亮太, 松井良太, 吉川徹, 蓑和健太郎, 竹内徹
    日本建築学会構造系論文集 84 763 1305 - 1313 2019年 [査読有り]
     
    © 2019 Architectural Institute of Japan. All rights reserved. A friction damper is one of useful displacement-depending energy dissipation devices; however, it is necessary to obtain the mechanical characteristics of each friction material through various experiments. Also the conventional design methods obtaining the optimal damper stiffness distribution to adjust response story drift angle to target values is inconvenient for friction dampers. In this paper, dynamic loading tests for friction dampers with different kinds of materials are conducted, and characteristics of each material are compared. Further, an alternative method to design the response-controlled structures with optimal friction damper distributions based on the strength index is proposed, and their validity is confirmed.
  • 松井良太, 有賀 惇, 森下邦宏, 加藤基規, 竹内 徹
    日本建築学会構造系論文集 84 761 973 - 982 2019年 [査読有り]
     
    © 2019 Architectural Institute of Japan. All rights reserved. The authors have proposed a phenomenological fiber model to simulate local buckling behavior of steel structural components in building frames. This phenomenological model captures development of the plastic strain localization of steel columns subjected to high axial load. This study presents the accuracy of the phenomenological fiber models applied to truss members. As a result, the phenomenological fiber model simulates the force-deformation relationship of the truss members including local buckling. This phenomenological fiber model is used for numerical simulation of a braced steel frame with incremental dynamic analysis to investigate the effect of local buckling on the ultimate seismic performance.
  • 松井良太, 橋本舟海, 竹内徹
    日本建築学会構造系論文集 84 760 863 - 873 2019年 [査読有り]
  • 松井良太, 友枝勝登, セットラー・ベン, 竹内 徹, 三原早紀, 帆足勇磨
    日本建築学会構造系論文集 84 758 563 - 573 2019年 [査読有り]
     
    © 2019 Architectural Institute of Japan. All rights reserved. Global out-of-plane stability of buckling-restrained braces is often governed by yielding of the neck. The authors previously proposed a method9) to evaluate this buckling mechanism, including the gusset rotational stiffness, connection length and neck - restrainer flexural continuity. While the proposed method has shown good agreement with experimental and numerical studies, this paper revisits a key assumption in the derivation, where the neck is modelled as an elasto-perfectly plastic hinge. Detailed FEM studies of a chevron BRB experiment with a range of gusset and framing boundary conditions are conducted, and an inelastic buckling model inspired by Shanley’s theory introduced.
  • 原田公明, 入口直樹, 寺澤友貴, 松井良太, 山崎義弘, 坂田弘安, 竹内徹
    日本建築学会構造系論文集 84 755 51 - 59 2019年01月 [査読有り][通常論文]
     
    © 2019 Architectural Institute of Japan. All rights reserved. In our previous paper, the static rigidity and the flexural strength at the joint of the lattice shell with the timber steel hybrid connection were clarified by static experiments and their effect on the buckling behavior of the entire roof was revealed by elastic buckling analysis. Here we examine the influence of the rotational stiffness of the connections on natural oscillation and earthquake response characteristics. Also the accuracy of the response spectrum evaluation using CQC method and the equivalent static seismic load are verified, followed by a simplified evaluation method proposal for the effect of rotational stiffness at connections.
  • 寺澤友貴, 稲永匠悟, 松井良太, 竹内徹
    日本建築学会構造系論文集 83 754 1789 - 1799 2018年12月 [査読有り][通常論文]
     
    © 2018 Architectural Institute of Japan. All rights reserved. Large numbers of structural and non-structural components in steel roof gymnasiums with RC substructures were damaged in the past earthquakes. Particularly in 2016 Kumamoto earthquake, structural component in some space frame roofs experienced serious damages including buckling, post-buckling fracture and fallings, which could have caused serious human damages. This paper presents the damage mechanism of space frame roofs with the effects of cantilevered RC walls based on numerical simulations of member-by-member models considering member buckling and fractures. The numerical simulation results were analyzed by comparison with the actual damages.
  • Seismic performance evaluation of single damped-outrigger system incorporating buckling-restrained braces
    Pao-Chun Lin, Toru Takeuchi, Ryota Matsui
    Earthquake Engineering & Structural Dynamics 47 2243 - 2265 2018年12月 [査読有り][通常論文]
  • 熊谷知彦, 六本木元太, 高橋寿太郎, 松井良太, 竹内徹
    日本建築学会構造系論文集 83 752 1465 - 1475 2018年10月 [査読有り][通常論文]
     
    © 2018 Architectural Institute of Japan. All rights reserved. In recent years, damages such as member buckling and falling of ceilings and lightings have occurred in relatively new gymnasiums. In order to solve these damages, introduction of seismic isolation system to spatial structures is cited. Above all, spherical sliding bearing (SSB) has a characteristic its natural period does not depend on the supported weight. Therefore, SSB is considered to be a seismic isolation system suitable for spatial structures consisting of steel members and having light dead load. From these backgrounds, the seismic response behavior of cylindrical lattice arch roofs supported by SSBs by shaking table tests are investigated.
  • 稲葉祐介, 寺澤友貴, 松井良太, 熊谷知彦, 竹内徹
    日本建築学会構造系論文集 83 751 1263 - 1272 2018年09月 [査読有り][通常論文]
     
    © 2018 Architectural Institute of Japan. Numerous steel roof bearings in RC gymnasia were damaged at the 2011 Tohoku and 2016 Kumamoto Earthquake, mainly due to out-of-plane response of cantilevered RC walls. Although the authors confirmed the reduction effect for seismic response of cantilevered RC walls by friction damper bearings, the transverse response evaluation methods including the roof response are not established. In this paper, using the experimental results of a PTFE sliding bearing, a friction damper bearing, and a rubber sheet bearing, the transverse response of RC walls are analyzed by numerical simulations including effects of the roof response, followed by proposing the evaluation methods.
  • 径厚比の大きな円形鋼管部材で構成された鉄塔支持型煙突の崩壊機構
    松井良太, 中村毅, 今村晃, 竹内徹
    日本建築学会構造系論文集 83 750 1171 - 1181 2018年08月 [査読有り][通常論文]
  • 種々の鉄骨屋根支承部の繰り返し載荷実験および屋根応答への影響
    稲葉祐介, 寺澤友貴, 松井良太, 熊谷知彦, 竹内徹
    日本建築学会構造系論文集 83 751 1129 - 1137 2018年08月 [査読有り][通常論文]
  • Seismic Performance and Evaluation of Controlled Spine Frames Applied in High-rise Buildings
    X. Chen, T. Takeuchi, R. Matsui
    Earthquake Spectra 34 3 1431 - 1458 2018年08月 [査読有り][通常論文]
  • 原田公明, 中島舜, 山崎義弘, 松井良太, 林賢一, 坂田弘安, 竹内徹
    日本建築学会構造系論文集 83 746 577 - 587 2018年04月01日 [査読有り][通常論文]
     
    In recent years, creating lattice shell roof structures with timber members are getting popularity due to its light weight and aesthetics: However, the one of their major difficulty is the connection details. In this research, a connection details for a rectangular laminated timber with a T-shaped or H-shaped cross section with lag screws are proposed to maintain flexural rigidity and tolerance of timber single layer lattice shell roofs. Their out-of-plane flexural strength and rotational rigidity of the proposed joint are verified by full-scale experiments, followed by the buckling strength evaluation formulas including the effects of connection stiffness.
  • 箕輪健一, 柴田恵実, 松井良太, 竹内徹, 小河利行
    日本建築学会構造系論文集 82 740 1653 - 1662 2017年10月01日 [査読有り][通常論文]
     
    Application of energy dissipation devices for the passive vibration control of truss towers has been recently researched, because these towers were generally designed to resist wind load. However, as the earthquake load requirements increases, these towers are possibly to be damaged by large earthquakes. On the other hand, researchers have developed semi-Active control device that produces any adjustable control force using variable dampers. This paper describes an investigation of applying semi-Active control system to truss towers using variable dampers. First, hysteresis of variable dampers is examined using DDOF system. Second, the semi-Active control system is applied to the truss towers to confirm the seismic response reduction compared with the passive vibration control.
  • 寺澤友貴, 松井良太, 中村毅, 竹内徹
    日本建築学会構造系論文集 82 739 1485 - 1495 2017年09月01日 [査読有り][通常論文]
     
    It is concerned that a long-duration earthquake in the future generates fatigue fractures in the steel structural components. The authors have investigated the member fracture of axial members including cold-formed circular hollow sections. According to previous study of steel braced frames, it's suggested that more ductile structural components should be applied to a steel structure achieving higher seismic performance. On the other hand, it is needed to develop an aseismic design method of a steel braced frame taking member fracture into account of frequent middle or large earthquakes. In this paper, the interaction of cumulative deformation capacity between a circular hollow section brace with different diameter thickness ratio and a steel frame is investigated for extending basic knowledge of ultimate seismic resistance of steel braced frame, using finite element analysis, experiments including shaking table testing and evaluation of ductility factor.
  • 竹内徹, 内田正颯, 松井良太
    日本建築学会構造系論文集 82 739 1339 - 1347 2017年09月01日 [査読有り][通常論文]
     
    Although the performance of seismic isolation devices as rubber bearings or dampers have been tested and evaluated through unidirectional input, actual seismic response working on these devices are bidirectional. Recently the performance of high-damping rubber bearings is found to be different from those under unidirectional input, and bidirectional tests for various isolation devices are being carried out. In this paper, bidirectional shaking table tests for SSB (Spherical Sliding Bearing/Friction Pendulum Bearing: FPB) are carried out, and the difference of their response against unidirectional response is researched. Found bidirectional effects are discussed using analytical model taking these effects into account, followed by the studies on the effects on the response of supported superstructures.
  • X. Chen, T. Takeuchi, R. Matsui
    JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 135 242 - 252 2017年08月 [査読有り][通常論文]
     
    A controlled spine frame system consisting of an elastic moment frame, elastic spine frame and concentrated yielding elements is proposed to ensure continuous usability of buildings in the event of an earthquake exceeding the design level. Prior studies have documented the excellent performance of spine frame structures in preventing both the concentration of damage in soft stories as well as in providing self-centering. The current study develops a simplified design method based on equivalent dual multi-degree-of-freedom and single-degree of -freedom representations, discussing the effects of damper yield drift, and stiffness ratios between the elastic moment frame, spine frame, and dampers on the structural response. This design method is validated with a parametric study and optimal ranges of the stiffness ratios are provided.
  • 藤下和浩, 松井良太, スッチュ・ファーティフ, 竹内徹
    日本建築学会技術報告集 23 53 147 - 152 2017年02月01日 [査読有り][通常論文]
     
    On the retrofit of existing sub-standard RC building with buckling restrained braces (BRBs), the insulation of elastic steel frame around BRBs is effective for restraining the residual deformation and the distribution of damage to whole structure. On this paper, the nonlinear hysteresis of steel frame member including the composite effect observed during the previous cyclic loading test is modelled to investigate its influence on the over-all structural response. Also, when the composite effect is unevenly distributed on each retrofit member, the worst distribution case of the composite effect is searched with genetic algorithm on the aspect of seismic performance is investigated.
  • 松井良太, 稲葉祐介, 竹内徹
    日本建築学会構造系論文集 82 731 115 - 122 2017年01月01日 [査読有り][通常論文]
     
    1. Introduction: The long period and long duration ground motions of the 2011 Tohoku Earthquake caused large deformations in tall (> 80 m) braced steel moment frames. Many engineers and researchers have claimed the damage observed at the beam-ends in these high-rise buildings. Thus, one of urgent tasks is to develop a simple method for screening vulnerability of the beam-ends in braced steel moment frames. Some researchers have proposed several evaluation methods to capture damages at the beam-ends. In this paper, the validity of those methods is investigated, considering fracture of braces, and a simple is proposed that does not require time consuming time history response analysis. 2. Response of Braced Steel Moment Frames under Long Period and Long Duration Ground Motion: First, an approximately 85 m height building model is created to examine the accuracy of the proposed method for evaluation of the beam-end damage considering the brace fracture. 10 long period and long duration artificial ground motions, scaled to 3 kinds of velocity spectrums: 160, 120, 80 cm/s, and 2 observed ground motions, scaled to the velocity spectrum of Building Code in Japan, are adopted as input ground motions. This analysis suggests that the damage distribution of the beam-ends is similar to the story drift distribution. Observation of previous analysis shows that damage of the beam-ends with a weld access hole is frequently larger than those with no hole. 3. Accuracy of Proposed Damage Evaluation Method by Previous Researcher: The accuracy of a damage evaluation method using Manson-Coffin rule previously proposed by a researcher (Manson-Coffin method) is investigated. Miner's rule is used for the evaluation of the beam-end damage in the method, which is largely consistent with static testing results. Another evaluation method using local strain at a beam-end proposed by the authors is fitted to the Manson-Coffin method to improve the accuracy. 4. Reference Ductility Ratio for Damage Evaluation: The number of cycles at each ductility ratio is required to evaluate the damage of the beam-ends using the Miner's rule. This method involves running a time history analysis program. Several ductility ratios are introduced as a reference to reduce calculation time for the damage evaluation of the beam-end. Damage values of the beam-end calculated by one of the reference ductility ratios are consistent with those by the time history response results within a margin of error of plus or minus 30%. 5. Index for Screening Vulnerability of Beam-ends in Braced Steel Moment Frames: The energy ratio is introduced, defined as the earthquake energy spectrum VE to the maximum velocity spectrum Sv. For RE = 2.0-3.5 and a maximum velocity is close to 160 cm/s, the beam-end fracture is likely. RE is promising an index to determine the damage of the beam-end. 6. Conclusions: This research investigated the damage evaluation of beam-ends in braced steel moment frames during a long period and long duration motion. The results are summarized as follows. 1) The damage distribution of the beam-ends is likely to be similar to the story drift distribution. The damage of the beam-end with a weld access hole is frequently larger than that with no hole. 2) Damage values of the beam-ends calculated by one of the reference ductility ratios are consistent with those by the time history response results with a margin of error of plus or minus 30%. 3) When the maximum velocity is close to 160 cm/s and the RE ranges from 2.0 to 3.5, the beam-ends are likely fracture.
  • Abhilasha Maurya, Matthew R. Eatherton, Ryota Matsui, Steven H. Florig
    JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 127 54 - 65 2016年12月 [査読有り][通常論文]
     
    This paper presents the design and experimental investigation of a miniature buckling-restrained brace (MBRB) which can act as a hysteretic damper to dissipate energy when subjected to inelastic axial deformations. The MBRB is similar to a buckling restrained brace (BRB) with a yielding steel core plate restrained from buckling by a grouted restraining tube. The MBRBs, however, are designed to have shorter lengths, smaller steel core dimensions, and smaller yield capacity as compared to a typical BRB. As a result, careful consideration is required for the detailing at the ends and the stability of the MBRB. Small capacity BRBs can be useful in a range of applications as a primary energy dissipating structural fuse or supplementary axial hysteretic damper in seismic force resisting systems. The design, construction, and testing of six MBRB specimens with nominal axial yield forces between 30 kN and 95 kN are reported. Issues related to global stability of the MBRBs are discussed and a stability criterion to prevent global buckling was adopted to design the MBRB end connection pieces. The MBRBs exhibited cumulative plastic deformations between 181 and 400 times the yield deformation and cumulative plastic strain between 46% and 106%. Conclusions about the behavior and recommendations for the design of the MBRB are presented. (C) 2016 Elsevier Ltd. All rights reserved.
  • Toru Takeuchi, Ryota Matsui, Saki Mihara
    EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS 45 12 1895 - 1917 2016年10月 [査読有り][通常論文]
     
    One of the key limit states of buckling-restrained braces (BRBs) is global flexural buckling including the effects of the connections. The authors have previously proposed a unified explicit equation set for controlling the out-of-plane stability of BRBs based on bending-moment transfer capacity at the restrainer ends. The proposed equation set is capable of estimating BRB stability for various connection stiffnesses, including initial out-of-plane drift effects. However, it is only valid for symmetrical end conditions, limiting application to the single diagonal configuration. In the chevron configuration, the out-of-plane stiffness in the two ends differs because of the rotation of the attached beam. In this study, the equation set is extended to BRBs with asymmetric end conditions, such as the chevron configuration. Cyclic loading tests of the chevron configuration with initial out-of-plane drifts are conducted, and the results are compared with the proposed equation set, which is formulated as a function of the normalized stiffness of the attached beam. (c) 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd. (c) 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.
  • 竹内徹, 松井良太, 長路秀鷹, 森下邦宏
    日本建築学会構造系論文集 81 728 1723 - 1732 2016年10月01日 [査読有り][通常論文]
     
    In the heavy plant structures as thermal power plants composed with the braced frame structures, the H-section columns receive bending moment under high axial force ratios. In such conditions the columns is tend to cause local and overall buckling under axial forces and bending moments. It is difficult to express the collapse characteristics of columns under such conditions with multi-spring models because the yield areas distributes not only at the ends of the columns but along the member. However, modeling all such columns as detailed FEM models is still time-consuming and not practical in structural design. To solve such problem, a single-dimensioned macro-member model composed of fiber elements is proposed in this paper. Each element has the hysteresis of local buckling characteristics and hence can express the local and overall buckling phenomena with simple element which can be easily plugged into time-history analyses. The validity of the proposed element is compared with experiments and FEM models with shell elements, followed by the discussions on their accuracies.
  • 藤下和浩, バル・アフメット, スッチュ・ファーティフ, 松井良太, 寺嶋正雄, チェリック・ジェム・オグゥツ, 竹内 徹
    日本建築学会構造系論文集 81 727 1575 - 1584 2016年09月01日 [査読有り][通常論文]
     
    Strength and stiffness of panel and joint in non-diaphragm CHS-column to H-beam connection were experimentally investigated Herein, the panel means the cylindrical stub circumscribed by outer planes of the beam and the column, and the joint means the butt seam between the column wall and the beam end. Two types of specimen were tested: one is an X-shaped frame whose panel is subjected to shear, and the other is a 3-point bending specimen whose panel is free from shear. In result, the joint strength and stiffness are well predicted by the previously proposed formulae irrespective of the existence of shear in the panel, and the panel strength and stiffness are also well predicted by the well known formulae given for diaphragm connections. This suggests that the interaction between panel and joint of the non-diaphragm connection can be ignored in structural design.
  • 松井良太, 寺澤友貴, 竹内徹
    日本建築学会構造系論文集 81 727 1553 - 1563 2016年09月01日 [査読有り][通常論文]
     
    The authors have proposed a method to assess local fracture of concentric braced frames under cyclic loading from global member results termed the Direct Local Strain Evaluation Method. In this method there is no need to use detailed member shell models to estimate the strain at the fracture point in the braces. This enables accurate time history response analysis using less computationally intensive stick models, while including the effect of local member fracture. However, up to now, the accuracy of the proposed method has only been validated under static loading. This research validates the proposed method with dynamic numeric and shake table testing. The proposed method is effective in simulating the braced frame response including the brace fracture under dynamic loading.
  • 成田和彦, 竹内徹, 松井良太
    日本建築学会技術報告集 22 50 41 - 46 2016年02月01日 [査読有り][通常論文]
     
    In the 2011 Tohoku Earthquake, a large number of school gymnasia suffered damage. One of the most typical damage observed in steel roof gymnasia supported by the RC frame is failure at the anchored connections of steel roof bearings on the RC frame. In this paper, the practical evaluation methods that we proposed in our past papers, of the reaction forces at the anchor connections, of the displacements at the roller bearings, and of the design requirements for the friction dampers, are compared with the time history analysis results.
  • 竹内徹, 吉田道保, 内田正颯, 西雄士, 松井良太
    日本建築学会構造系論文集 81 721 629 - 637 2016年 [査読有り][通常論文]
     
    The seismic response of rack warehouses is known to be reduced by horizontal sliding of 1he warehouse contents, which act as mass dampers. However, in past earthquakes business continuity has been interrupted due to damage from spilling, toppling or falling contents. In this paper, response control using seismic isolation is investigated. Because the total rack weight is constantly changing and tie rack is often loaded at large eccentricities, Spherical Sliding Bearings (SSB) are proposed, which exhibit natural periods independent of the supported weight. Based on numerical and experimental test results undertaken previously, an analytical model is proposed including pressure and velocity dependent friction values. Using He proposed model, the performance of a seismically isolated rack warehouse with variable weight and eccentricity is studied and compared with conventional rubber bearings.
  • 藤下和浩, スッチュ・ファーティフ, 松井良太, 竹内徹
    日本建築学会構造系論文集 81 721 537 - 546 2016年 [査読有り][通常論文]
     
    Damper distribution rule with equivalent linearization method on seismic control retrofit for overseas brittle RC buildings was proposed by die authors. However, tins result is not necessarily proved as optimal. Recently. Genetic Algorithm (GA) is applied to solve numerous kinds of structural optimization problems, mainly in the range of static analysis, hi this paper, the optimization method of damper distribution with GA using elasto-plastic dynamic analysis for multi degree of freedom shear spring model is proposed. By using proposed optimization method, the optimal damper distribution defined as minimum damper distribution satisfying die target stray drift angle for seismic retrofit, is obtained. Finally, comparison of die results with GA and solutions with equivalent linearization method is represented and the effectiveness of proposed damper distribution rule is discussed.
  • Optimal Arrangement of Energy-Dissipating Members for Seismic Retrofitting of Truss Structures
    Toru Takeuchi, Yusuke Kinouchi, Ryota Matsui, Toshiyuki Ogawa
    American Journal of Engineering and Applied Sciences 8 4 455 - 464 2015年11月 [査読有り][通常論文]
  • T. Takeuchi, X. Chen, R. Matsui
    JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 114 51 - 65 2015年11月 [査読有り][通常論文]
     
    Recently, various controlled rocking systems have been proposed in seismic design to prevent damage concentration and to achieve self-centering against a wide range of input ground motion intensities. However, several obstacles must be overcome before these systems can be applied to actual buildings; for example, the requirement for large, self-centering post-tensioned strands and special treatment at uplift column bases must be addressed. This paper proposes a non-uplifting spine frame system with energy-dissipating members without post-tensioned strands, its self-centering function is achieved by envelope elastic-moment frames. The system is applied to an actual building constructed in Japan. Conventional shear damper and uplifting rocking systems with post-tensioned strands developed in prior studies are also applied to the same building structures, and the performances of the three systems, including damage distribution, energy dissipation, self-centering, robustness against severe earthquakes, and irregular stiffness, are compared and discussed through numerical simulations based on practical design criteria. (C) 2015 The Authors. Published by Elsevier Ltd.
  • 竹内徹, 小崎均, 松井良太, 三原早紀
    日本建築学会技術報告集 21 49 1065 - 1070 2015年10月01日 [査読有り][通常論文]
     
    One of the key limits of buckling-restrained braces (BRBs) is overall flexural buckling caused by connection failure, and they are required to exhibit stable hysteresis under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion. In this paper, a series of cyclic loading tests with initial out-of-plane drifts for double web H type BRB and pin-ended tube-in-tube BRB are carried out, and the stability performance including various connection conditions and initial out-of-plane drifts are researched. These results are compared with the stability evaluation equations proposed by the authors, and the validity and accuracy of these equations are discussed.
  • Toru Takeuchi, Ryota Matsui
    JOURNAL OF STRUCTURAL ENGINEERING 141 7 2015年07月 [査読有り][通常論文]
     
    The postbuckling behavior of seismic-resistant braces in steel frames under a cyclic axial force is often evaluated by time-history analyses; however, brace fracture is seldom considered. The authors previously proposed a physical model for predicting the moment of fracture of circular-tube braces after buckling using phenomenological hysteresis. However, the accuracy of that model was confirmed only against the test results of the gradually increasing amplitude loading protocol, and its applicability under other loading histories has not yet been verified. In this study, cyclic loading tests were carried out until fracture on circular-tube and H-section braces under various loading histories, followed by FEM analyses. The validity of the proposed formulas for evaluating the strain-concentration index under various loading histories was examined. The proposed method was used for predicting the moment of fracture and the cumulative deformation capacity until fracture, and the predictions agreed well with the test results.
  • 二方向地震動入力を受ける座屈拘束ブレース付鉄骨架構のブレース構面外応答
    小崎均, 長路秀鷹, 松井良太, 竹内徹
    構造工学論文集 61B 401 - 408 2015年03月 [査読有り][通常論文]
  • Seismic effect of members fracture on truss tower
    Ryota Matsui, Toru Takeuchi, Kentaro Horiuchi, Akira Imamura, Toshiyuki Ogawa
    IABSE Conference, Nara 2015: Elegance in Structures - Report 396 - 397 2015年 
    The ultimate strength of truss tower structures is governed by buckling of tubular members which easily leads to the member fracture. This paper proposes the post-fracture analysis methods for truss structures composed with tubular members with high diameter-to-thickness ratios, and a study on the collapse mechanism of such truss towers after buckling and fracture of members is investigated using incremental dynamic analysis (IDA) analysis. Truss towers without stack members exhibited collapse after buckling of main columns or fracture of diagonal members.
  • 松井良太, 潤井駿司, 得能将紀, 竹内徹
    日本建築学会構造系論文集 80 717 1745 - 1754 2015年 [査読有り][通常論文]
     
    The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large scale and long period ground motion. Recently the higher level of the earthquake ground motion is considered in structural design, and the nonlinearity characteristics such as large plasticity or fracture of members are inevitable issues in seismic performance evaluation of the steel structures. This paper presents the seismic performance of the braced frames is assessed by the time history response analysis program taking fracture of the end of beams and braces into account. The incremental dynamic analysis (IDA) is hired, in order to grasp the ultimate state under extremely large ground motions. The fragility curve was constituted from the analysis results, which provides the member fracture has definitely effect on the seismic performance of the braced frames.
  • 成田和彦, 寺澤友貴, 前原航, 松岡祐一, 松井良太, 竹内徹
    日本建築学会構造系論文集 80 717 1717 - 1725 2015年 [査読有り][通常論文]
     
    A large numbers of steel roof bearings in RC gymnasia are damaged at past earthquakes at the 2011 Tohoku Earthquake, mainly due to the out-of-plane response of cantilevered RC walls supporting the roof frame. In the conventional seismic retrofit method, bearings reinforcement with steel corner plates and replacement of all the roof braces are required, therefore uneconomical. In this paper, a detailed energy-dissipation bearing with friction dampers for steel roof reducing the response of cantilevered RC walls is fabricated and dynamic loading tests are carried out. Using the experimental results, their response reduction effect is confirmed by analytical models.
  • 竹内徹, 中村秀司, 内田正颯, 吉田道保, 松井良太
    日本建築学会構造系論文集 80 715 1385 - 1392 2015年 [査読有り][通常論文]
     
    Although rubber bearings are popular for seismic isolation bearings in Japan, Spherical Sliding Bearings (SSB) or Friction Pendulum Bearings (FPB) are also widely used in many countries including U. S. In this paper, shaking table tests on braced frame supported by SSB are carried out, and their dependency on pressure and velocity is examined. Also tests with the eccentric dead loads are conduted, in order to capture lift-up actions at bearings and their performance. Analytical models taking pressure and velocity dependency into accounts are proposed, and their validity against the experimental results are discussed.
  • 成田和彦, 竹内徹, 松井良太
    日本建築学会構造系論文集 80 708 273 - 283 2015年 [査読有り][通常論文]
     
    In the 2011 Tohoku Earthquake, a large number of school gymnasia suffered damage and were unable to be used as shelters. One of the most typical damage observed in steel roof gymnasia supported by RC frame were failures at the anchored connections of steel roof bearings on RC frames. In the previous paper, we have discussed on the response of cantilevered RC walls supporting steel roofs using analytical model of a damaged gymnasium in the 2011 Tohoku earthquake, and the obtained analytical results were evaluated on the observed damage. In this paper, the action of cantilevered RC walls supporting steel roofs is investigated using parametric analysis model of various school gymnasia. Based on the analytical results, a simple response evaluation method for the cantilevered frames and reaction forces at roof bearings are proposed.
  • 成田和彦, 寺澤友貴, 松井良太, 竹内徹
    日本建築学会構造系論文集 80 707 157 - 165 2015年 [査読有り][通常論文]
     
    Introduction: A largelarge number of steel roof bearings in RC gymnasia are damaged at 2011 Tohoku Earthquake, and out-of-plane response of cantilevered RC walls supporting the roof frame is identified as one of main causes of damage. In order to use these kinds of gymnasia as shelters after the earthquake, they are required seismic retrofit. However, a conventional seismic retrofit method requires strengthening bearings with steel corner plates and replacing all the roof braces, which is uneconomical. In this paper, a seismic retrofit method inserting energy-dissipation elements into the roof bearings is discussed and their response reduction effects on the gymnasium are investigated. 2. Modelling and Response of Non-Retrofitted Model: The analysis model simulates the actual gymnasium damaged in 2011 Tohoku earthquake and the energy-dissipation roof bearings with elasto-plastic or viscous damper are taken into account. The maximum acceleration response of non-retrofitted model at the bearings is about 2.5∼3.0G and the maximum reaction force of bearings is over the yield force of the existing bearings, which corresponds to the actual damage. The maximum acceleration response of non-retrofitted model at the roller bearings is reduced to 1.5G, however, the maximum displacement of the RC cantilevered walls reaches over 300 mm. 3. Response of Retrofitted Model with Energy-Dissipation Bearings: On the basis of the analysis results, a seismic retrofit method using the energy-dissipation bearings shows the significant response reduction effect on the RC cantilevered walls. In the retrofit using the elasto-plastic bearings, the maximum displacement response of the RC cantilevered walls is reduced sufficiently by initial stiffness and limited yield strength bearings. Then, the maximum relative displacement of bearings is suppressed below 50 mm. In the studies of retrofit using the viscous bearings, the maximum displacement and acceleration response of the cantilevered RC walls and the maximum relative displacement of bearings are reduced to a certain extent simultaneously as viscous increases. Then, the maximum reaction force of bearings is kept below the yield force of the existing bearings and the maximum relative displacement of bearings is suppressed below 20 mm. 4. Response Evaluation with equivalent SDOF System and Equivalent Linearization Method: A simplified response evaluation method using the equivalent SDOF system and equivalent linearization method are proposed to analyze the response of the cantilevered RC walls and to determine the optimum performance of the energy-dissipation bearings. The model is composed of the steel roof spring, the cantilevered RC wall mass and spring and the bearings as a non-linear spring. Analysis with equivalent SDOF system can evaluate the maximum reaction force of bearing and the evaluation of their maximum displacement in a safe side. 5. Conclusions: In conclusions, the following results are obtained. 1) A seismic retrofit method inserting energy-dissipation elements into roof bearings shows significant response reduction effect on RC cantilevered walls, keeping boss the reaction force and displacement of bearings non-damaged level. 2) The energy-dissipation bearings with elasto-plastic damper show the significant response reduction effect on the cantilevered RC walls with high stiffness and limited yield strength, while the maximum relative displacement of bearings is suppressed below 50 mm. 3) The energy-dissipation bearings with viscous damper also show the significant response reduction effect on RC cantilevered walls. Both the maximum displacement and acceleration response and the maximum relative displacement of bearings are reduced to non-damaged level, the maximum relative displacement of bearings being suppressed below 20 mm. 4) A simplified response evaluation method using equivalent SDOF system and an equivalent linearization technique are proposed to determine the optimum specification of the energy-dissipation bearings with some margins in the maximum displacement.
  • Fatih Sutcu, Toru Takeuchi, Ryota Matsui
    JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 101 304 - 313 2014年10月 [査読有り][通常論文]
     
    Existing RC buildings conforming to relatively older regulations and codes may lack in seismic resistance. This is especially true for public buildings such as schools or hospitals, which demand efficient retrofitting to ensure safety during and after a seismic event. Although retrofit design with conventional braces (CB) has been practiced for decades, the unbalanced hysteresis behavior of CBs tends to result in damage concentrated in specific stories. Buckling-restrained braces (BRBs), a new generation of bracing system, may increase structural integrity and at the same time reduce seismic response in a building via energy absorption. However, when the maximum story drift exceeds the yield point of RC frame, all structural elements including BRBs lose horizontal stiffness, which may result in both damage at a specific story and residual deformation effects occurring after an earthquake. Therefore, BRBs may be applied to such buildings using elastically designed steel frames (SF). This paper discusses the evaluation of damage distribution and self-centering functions of the elastic steel frames that connect BRBs to RC frames. In addition, we propose a simplified method based on equivalent linearization to design the required amount of BRB and elastic SF capacity for retrofitting existing RC buildings. The results were confirmed by nonlinear time:history analysis using high-intensity seismic waves. The results show that RC buildings retrofit with BRBs respond as predicted by the proposed method and target story drift is obtained. The story drifts of the BRB retrofit model is significantly reduced relative to both the original building and the building retrofit with CBs. In addition, because BRBs are attached to an existing building by elastically designed steel frames, the significant effect of SF on the reduction of residual displacements was also shown and discussed. (C) 2014 Elsevier Ltd. All rights reserved.
  • 竹内徹, 堀内健太郎, 松井良太, 小河利行, 今村晃
    日本建築学会構造系論文集 79 703 1309 - 1319 2014年09月01日 [査読有り][通常論文]
     
    Although truss towers used for telecommunication, electric power transportation, supporting structures for smokestacks in power plants have been designed against wind loads, a higher level of safety is recently required because of the increase of anticipated large seismic inputs. The ultimate strength of these structures is governed by tubular member buckling which is easily led to member fracture. This paper proposes the post-fracture analysis methods for truss structures composed with tubular members of large diameter-to-thickness ratios, and study on the collapse mechanism of such truss towers after the buckling and fracture of main columns and diagonals are investigated, using IDA analyses taking these member fractures into account.
  • 松井良太, 廣山剛, 竹内徹
    日本建築学会構造系論文集 79 702 1183 - 1191 2014年08月01日 [査読有り][通常論文]
     
    Circular hollow sections (CHS) are widely used as bending members in many structures including moment resisting frames. Several structural design provisions such as CIDECT suggest hot spot method and classification method for assessment of fatigue performance of CHS welded joints particularly in the elastic range. By contrast, the authors have proposed a strain concentration method of H-section beams which requires only displacement at the end of the macro-members to assess the cyclic plastic deformation capacity. This paper presents the experiments on four types of CHS T-joints subjected to cyclic bending moment to investigate the strength and the cumulative plastic deformation capacity. Finite element analysis was used to examine the plastic strain distribution at the strain concentration zone of the CHS T-joints. The strain concentration ratio of the CHS T-joints was established by those testing and numerical results. It was found that the cumulative plastic deformation capacity of the CHS T-joints assessed by the proposed method is by and large consistent with the testing results.
  • Toru Takeuchi, Hitoshi Ozaki, Ryota Matsui, Fatih Sutcu
    EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS 43 6 851 - 869 2014年05月 [査読有り][通常論文]
     
    Buckling-restrained braces (BRBs) are widely used as ductile seismic-resistant and energy-dissipating structural members in seismic regions. Although BRBs are expected to exhibit stable hysteresis under cyclic axial loading, one of the key limit states is global flexural buckling, which can produce an undesirable response. Many prior studies have indicated the possibility of global buckling of a BRB before its core yields owing to connection failure. In this paper, BRB stability concepts are presented, including their bending-moment transfer capacity at restrainer ends for various connection stiffness values with initial out-of-plane drifts, and a unified simple equation set for ensuring BRB stability is proposed. Moreover, a series of cyclic loading tests with initial out-of-plane drifts are conducted, and the results are compared with those of the proposed equations. (c) 2013 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.
  • 積載物の滑動および落下を考慮した立体倉庫の地震応答制御
    松野勇輝, 竹内徹, 松井良太, 西雄士
    構造工学論文集 60B 569 - 574 2014年03月 [査読有り][通常論文]
  • 藤下和浩, 松井良太, 竹内徹
    日本建築学会構造系論文集 79 706 1961 - 1971 2014年 [査読有り][通常論文]
     
    In retrofitting multistory RC buildings which have uniaxial eccentricity, it is important to control torsional displacement to assure safety of' structure under seismic input. In this study, elastic response of each frame of uniaxial eccentric three-dimensional model is evaluated by using a pair of equivalent independent lamped mass models. The easy damper distribution method proposed for plane frames in the previous paper is applied to these pair of lamped mass, and damper distribution in each plane frame are determined. The validity of proposed method is confirmed by applying to three-dimensional model of typical Turkish RC building which has uniaxial eccentricity and weak stories.
  • 竹内徹, 陳星辰, 松井良太
    日本建築学会構造系論文集 79 706 1941 - 1949 2014年 [査読有り][通常論文]
     
    Recently, various controlled rocking systems have been proposed in seismic design to prevent damage concentration and to achieve self-centering against a wide range of input ground motion intensities. However, there are several obstacles to overcome before they can be applied to actual buildings, such as the requirement of large, self-centering post-tensioned (PT) strands and special treatment at uplift column bases. This paper proposes a non-uplifting spine frame system with energy-dissipating members without PT strands its self-centering function relies on envelope elastic moment frames. The system is applied to an actual building constructed in Japan. Conventional shear damper and uplifting rocking systems with PT strands developed in prior studies are applied to the same building structures, and the performance of the three systems, including damage distribution, energy dissipation, self-centering, robustness against severe earthquake, and irregular stiffness, is compared and discussed through numerical simulations.
  • 小崎均, 小西克尚, 松井良太, 竹内徹
    日本建築学会構造系論文集 79 706 1919 - 1929 2014年 [査読有り][通常論文]
     
    Buckling restrained braces (BRBs) are widely used in seismic regions as ductile seismic-resistant and energy dissipating structural members. On the other hand, the risk of overall flexural buckling under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion has been pointed out. In this regard, series of formula for securing the BRB out-of-plane stability has been proposed in previous studies. However, the actual ranges of each index that make up this series of formula are not clear for practical engineers. In this paper, these index values are clarified by carrying out the research studies of various BRBs and their connections that have been used in actual design. Based on these results, a simple method that can evaluate the out-of-plane stability condition of BRBs with various connection conditions is proposed.
  • 竹内徹, 松井良太, 三原早紀, 大家貴徳, 岡本勇紀, 小?均, 岩田衛
    日本建築学会技術報告集 20 45 569 - 574 2014年 [査読有り][通常論文]
     
    One of the key limits of buckling-restrained braces (BRBs) is overall flexural buckling caused by connection failure, and they are required to exhibit stable hysteresis under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion. In this paper, a series of cyclic loading tests with initial out-of-plane drifts for built-up type BRB is carried out, and the stability performance including various connection conditions and initial out-of-plane drifts are researched. These results are compared with the stability evaluation equations proposed by the authors, the validity and accuracy of these equations discussed.
  • 竹内徹, 木内佑輔, 松井良太, 小河利行
    日本建築学会構造系論文集 79 700 791 - 799 2014年 [査読有り][通常論文]
     
    Application of energy dissipation devices for the seismic retrofit of truss towers has been recently researched, because these structures have been generally designed against wind load, and are possibly to be damaged by large earthquake. Although the effect of energy dissipation devices has been confirmed, the arrangement methodology of these devices has not been established yet. In this study, optimization techniques are applied to arrangements of devices. Firstly, a response evaluation method using response spectrum and equivalent linearization method is proposed. Second, the proposed method is applied to the investigation of optimum arrangement of visco-elastic damper devices on a telecommunication tower. Additionally, the device arrangements by the conventional design methods are compared with the optimum solutions. The results demonstrate that the conventional design is significantly effective to determine the optimum device arrangement.
  • 藤下和浩, スッチュ・ファーティフ, 松井良太, 竹内徹
    日本建築学会構造系論文集 79 699 661 - 669 2014年 [査読有り][通常論文]
     
    When retrofitting reinforced concrete buildings in Turkey with energy-dissipation devices, damage distribution between each story become very important, because the ultimate horizontal shear strength in each story is lower than Japanese buildings, and damage concentration at specific story is highly expected. In this paper, a retrofit concept adding elastic frames together with hysteretic dampers is introduced, and the effects of these elastic elements for damage distribution were researched and discussed, also for use in structures including weak stories. The easy damper distribution method using equivalent linearization techniques including the effect of additional elastic frames is proposed, followed by its validity evaluations.
  • 竹内徹, 小崎均, 松井良太
    日本建築学会構造系論文集 78 691 1621 - 1630 2013年09月 [査読有り][通常論文]
     
    Buckling restrained braces (BRBs) are widely used in seismic regions as ductile seismic-resistant and energy dissipating structural members. One of the key limits of BRBs is overall flexural buckling, and they are required to exhibit stable hysteresis under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion. However, many researches are indicating that there are risks of overall buckling caused by connection failure, before the BRB core yields. In this paper, the stability conditions of BRBs including their various connection conditions and initial out-of-plane drift are discussed and a unified simple equation set for securing the BRB stability is proposed. Moreover a series of cyclic loading tests with initial out-of-plane drifts is carried out, and results are compared with the proposed index.
  • 松井良太, 廣山剛, 竹内徹
    日本鋼構造協会鋼構造論文集 20 79 11 - 18 Japanese Society of Steel Construction 2013年09月 [査読有り][通常論文]
     
    When braced moment frames are subjected to a strong ground motion, the bracing elements are likely to fracture. Such fracture results in a large cumulative plastic deformation at the beam end which leads to the connection failure. The authors have proposed a method to assess the brace and beam end fracture using time history response analysis without micro element FEM. However, this method does not take the beam end joint efficiency into account. In this study, the effect of the joint efficiency on the cumulative deformation capacity of the beam end is investigated. Using those results, the seismic performance of the braced moment frame is analyzed including the fracture of brace members and beam ends.
  • 竹内徹, 西牧誠, 松井良太, 小河利行
    日本建築学会構造系論文集 78 690 1503 - 1512 2013年08月 [査読有り][通常論文]
     
    Seismic retrofit of damaged steel school gymnasium with angle braces is often carried out by replacing damaged braces by larger section angle braces with ultimate strength designed connections. However, the effects of the replaced braces for the retrofit against expected seismic input are not confirmed yet. In this paper, a gymnasium damaged by Tohoku Earthquake 2011 was analyzed including the fracture conditions derived from cyclic tests of angle braces. Furthermore, retrofit options using angle braces with ultimate strength designed connections, strength based designed braces, and energy dissipating braces are analyzed using the same model, and their performances are compared including effects on the acceleration response along the roof.
  • 松井良太, 山浦夕佳, 竹内徹
    日本建築学会構造系論文集 78 690 1485 - 1492 2013年08月 [査読有り][通常論文]
     
    Lateral-torsional buckling is one of key factors that determine ductile behavior of steel moment frames. Current lateral bracing requirements for beams are established on the basis of monotonic loading conditions in Japanese seismic provisions. However, the relationship between the current provisions and lateral bracing stiffness requirements under cyclic loading conditions has not been confirmed systematically yet. In this study, an experimental study was conducted to assess the effect of lateral bracing stiffness on the H-section beam strength under cyclic loading. Three different lateral bracing types were examined under cyclic antisymmetrical moment. A numerical analysis is used to simulate the experimental results and compute the effects of lateral bracing stiffness, bracing span, stiffener and dead load condition on the H-section beam elasto-plastic lateral-torsional buckling behavior. The results are compared to the requirements of the current provisions and discussed.
  • 成田和彦, 竹内徹, 松井良太
    日本建築学会構造系論文集 78 693 1895 - 1904 2013年 [査読有り][通常論文]
     
    At 2011 Tohoku Earthquake, many school gymnasia suffered damages owing to not only Tsunami but the consequent shake. One of the most typical damages observed in steel roof gymnasia supported by RC frame are failures at the anchored connections of Steel roof bearings to RC frames. Such failures were observed in not only aged structure but recently designed gymnasia, which mean that further guideline is strongly required. However, evaluation of reaction forces at these connections is not easy because of complicated response characteristics between steel roofs and cantilevered concrete walls. In this paper, the action of cantilevered RC walls supporting steel roofs is researched using analytical model of actual damaged gymnasium in 2011 earthquake. The obtained analytical results are evaluated on the observed damages, and response characteristics of cantilevered RC walls are discussed, followed by proposal of easy design methods for these connections.
  • 竹内徹, 堀内健太郎, 松井良太, 渡辺和志
    日本建築学会構造系論文集 77 682 1969 - 1976 2012年12月 [査読有り][通常論文]
     
    Recently aluminum braces are used for seismic retrofit of reinforced concrete buildings. Aluminum braces reaches their maximum strength at similar story drift angle as reinforced concrete frames and have a priority to steel tube brace, which buckles where RC frames reaches their maximum strength. However, their cyclic performances after buckling are not confirmed yet. If they cause local buckling after overall buckling, they are expected to be fracture. In this paper, cyclic loading experiments on aluminum braces with pin-end connections are carried out until their fracture, and their performance after buckling is confirmed. Also applying the method for steel tube braces, easy fracture prediction method for aluminum braces is proposed and their validity is discussed.
  • T. Takeuchi, J. F. Hajjar, R. Matsui, K. Nishimoto, I. D. Aiken
    ENGINEERING STRUCTURES 44 44 304 - 311 2012年11月 [査読有り][通常論文]
     
    Buckling-Restrained Braces (BRBs) are commonly used as ductile bracing elements in seismic zones. Key limit states governing BRB design include preventing both flexural buckling and local buckling failures. In this study, the authors propose a strategy for the prevention of in-plane local buckling failure of a BRB whose restrainer is composed of a mortar in-filled circular or rectangular steel tube with various mortar thicknesses. Cyclic loading tests on BRBs possessing various mortar restrainers and circular tube thicknesses were carried out to investigate the effect of the mortar and the sectional shape of the restraint tube on the local buckling failure of buckling-restrained braces. (C) 2012 Elsevier Ltd. All rights reserved.
  • 竹内徹, 近藤佑樹, 西本晃治, 今村晃
    日本建築学会構造系論文集 77 681 1781 - 1790 2012年11月 [査読有り][通常論文]
     
    Seismic-resistant braces subjected to cyclic axial force is known to undergo low-fatigue fracture after local buckling, and theauthors have proposed an easy evaluation method predicting the fracture point of circular and H-section braces after buckling, using macro-member models. However, its validity against such members as built L-section or built C-section is not confirmed yet. In this paper, cyclic loading tests of built-up L, C, and T-section braces under cyclic loading histories are carried out, and FEM analyses following the test results are performed. Reflecting these results, the fatigue failure mechanisms of such braces are discussed including validities of the proposed method.
  • 竹内徹, 西牧誠, 松井良太, 今村晃
    日本建築学会構造系論文集 77 677 1131 - 1140 2012年07月 [査読有り][通常論文]
     
    The post-buckling behavior of the seismic-resistant braces in braced frames under cyclic axial force is often evaluated by time-history analyses however, they seldom consider brace fracture. Authors have proposed an easy evaluation method predicting the fracture point of the circular and H-section braces after buckling, using macro-models. However, the method is confirmed only against the test results of gradually increased amplitudes and applicability under other loading histories is not verified yet. In this paper, cyclic loading tests on the circular and H-section braces under various loading histories are carried out, and FEM analyses following the test results are performed. Reflecting these results, the validities of the proposed methods for the brace fracture prediction under various loading histories are discussed.
  • R. Matsui, T. Takeuchi
    STESSA 2012: PROCEEDINGS OF THE 7TH INTERNATIONAL CONFERENCE ON BEHAVIOUR OF STEEL STRUCTURES IN SEISMIC AREAS 607 - 613 2012年 [査読有り][通常論文]
     
    A Buckling Restrained Brace (BRB) comprises a steel core plate restrained by a mortar-filled steel tube. A key limit state of BRB is determined by the cumulative deformation capacity until the core plate fractures. This capacity decreases to that of the steel material. In this paper, the mechanism that decreases the cumulative deformation capacity of the BRB is explained by local buckling of the core plate, which leads to nonuniform strain distribution of the core plate in the longitudinal direction. The decrease in the cumulative deformation capacity of the BRB can be explained by applying the fatigue performance formula for the steel material to the strain at the local zone. A ratio that compares the strain concentration degree at the local zone with the total normalized deformation is proposed to determine the strain at the local zone relative to the total normalized deformation. In addition, the effect of the exponential value of the fatigue performance formula on the methods for predicting the cumulative deformation capacity of the BRB is investigated.
  • 竹内徹, 中村悠, 松井良太, 小河利行
    日本建築学会構造系論文集 76 669 1971 - 1980 2011年11月 [査読有り][通常論文]
     
    High-rise truss towers consist of steel tubular section members have high risks to be damaged by seismic input, because their hysteretic characteristics deteriorate after buckling and easy to fracture after local buckling However present design does not include the effect of such member fracture. Authors have established algorism to predict member fracture after buckling for tubular members using macro-model, derived from experimental and analytical studies. In this paper, this algorism is applied for time-history analyses and seismic responses of detailed tower structures are analyzed. The validity of proposed method is firstly compared with actual earthquake damages, followed by researches on the effect of member fracture in various truss towers.
  • Toru Takeuchi, Ryota Matsui
    JOURNAL OF STRUCTURAL ENGINEERING-ASCE 137 11 1311 - 1318 2011年11月 [査読有り][通常論文]
     
    Tubular-section members are commonly used as seismic-resistant braces because they have a higher moment of inertia than open cross sections of equivalent area. However, the cumulative cyclic deformation capacity of tubular sections after buckling is smaller than that of open sections, such as H-shaped sections, because fracture is initiated by local buckling of circular tubular sections. To evaluate the seismic performance of such diagonal braces, it is essential to predict the cumulative cyclic deformation capacity of these braces before any fracturing. In this study, the cumulative cyclic deformation capacity of circular tube braces under local buckling was assessed by performing cyclic loading tests for a range of slenderness and diameter-to-thickness ratios. The mechanism of strain concentration in the tubular braces was studied in various types of analysis, and a method is proposed for assessing the cumulative deformation capacity before fracture based on the entire axial deformation of the braces. DOI: 10.1061/(ASCE)ST.1943-541X.0000380. (C) 2011 American Society of Civil Engineers.
  • 竹内徹, 山本洋介, 緑川光正, 笠井和彦, ジェロム ハジャー, 引野 剛, 松井良太, 吉敷祥一
    日本建築学会構造系論文集 76 667 1695 - 1704 2011年09月 [査読有り][通常論文]
     
    The authors have conducted a series of experimental studies on the response characteristics of controlled rocking systems. This system comprises components that include a rocking frame, post-tensioning anchorages, and energy dissipation fuses, eliminating the residual deformation after the earthquake. In this paper, the shaking table test of the controlled rocking system using a Buckling Restrained Brace as the energy dissipation fuse is discussed, including analytical simulations. A procedure to estimate maximum response is introduced based on the concept using maximum instantaneous input energy. The characteristics of the input energy and the accuracy of the proposed approach are demonstrated by comparing the prediction with numerical results as well as experimental results.
  • 松井良太, 竹内徹
    日本建築学会構造系論文集 76 665 1337 - 1345 2011年07月 [査読有り][通常論文]
     
    A moment frame with bracing elements is one of efficient seismic-resistant stmctural system in elastic design, howevei when the seismic input is larger than the buckling strength of braces, these undergo local buckling subsequent to overall buckling, and the concentration of plastic strain at local buckling area easily leads to brace fracture. The authors have previously proposed a brace fracture prediction method. In this paper, time-history response analyses for braced frames are cathed out focusing on the brace fracture using the proposed method. A discussion follows fatigue distribution in the frame types, including the effect of the brace fracture itself.
  • 竹内徹, 近藤佑樹, 西本晃治, 松井良太
    日本建築学会構造系論文集 76 663 989 - 996 2011年05月 [査読有り][通常論文]
     
    A Buckling Restrained Brace (BRB) with serially connected tubular members is one of the solutions for composing BRB over 10m length economically for the seismic design of truss structures or large-span structures. Their overall buckling condition is considered to be sensitive for imperfections or eccentricities comparing to ordinary BRBs however, their effects are not confirmed by experiments yet. In this paper, the overall buckling conditions for BRBs with serially connected tubular members are discussed as the functions of imperfections or eccentricities. Their effects on the stability are confirmed by cyclic loading experiments until member fractures, and design criteria are proposed.
  • 竹内徹, 大山翔也, 松井良太
    日本建築学会構造系論文集 76 661 695 - 702 2011年03月 [査読有り][通常論文]
     
    Structural system composed of high-strength steel frame with energy-dissipation elements is one of the suitable solutions for damage tolerant structure. In this concept, the main structure is designed in elastic zone for design earthquake level however, there are still some risks to step into plastic zone in maximum considered earthquake levels. Because of high strength steel having high yield ratio, it is concerned to fracture early after yielding. In this paper, following the mock-up cyclic-loading tests and analysis of 800Mpa steel beam-column frame with diagonal BRBs, their fracture mechanism of beam-end connections are modeled using simple non-linear rotation springs, and estimation method for their cumulative energy dissipation capacities until their fractures in multistory structures are proposed.
  • 接合部固定度を考慮したH形断面ブレースの座屈後履歴性状及び累積変形性能
    竹内徹, 中村悠, 松井良太
    日本建築学会構造系論文集 75 653 1289 - 1297 2010年08月 [査読有り][通常論文]
  • T. Takeuchi, J. F. Hajjar, R. Matsui, K. Nishimoto, I. D. Aiken
    JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 66 2 139 - 149 2010年02月 [査読有り][通常論文]
     
    Buckling Restrained Braces (BRBs) are commonly used as bracing elements in seismic zones. A key limit state governing BRB design is to prevent flexural buckling. However. when the wall thickness of the steel tube restrainer is relatively small compared to the cross-section of the core plate. the restraint conditions against the local buckling of the core plate can be critical for the stability and strength of the BRB. In this study, cyclic loading tests and numerical analyses of BRBs were carried out using various tube restrainer configurations to investigate the influence of local buckling of the restrainer on BRB strength and ductility. (C) 2009 Elsevier Ltd. All rights reserved.
  • 竹内徹, 松井良太, 西本晃治, 高橋聡史, 大山翔也
    日本建築学会構造系論文集 74 639 925 - 934 2009年05月 [査読有り][通常論文]
     
    Buckling Restrained Braces (BRBs) are commonly used as doctile bracing elements in seismic design. A key limit of BRB is overall flexumi buckling. Howevei their effective buckling lengths are affected by the stifihess and strength of their connection zones. In this paper, each connection zone is modeled as two rotational elastic springs at gusset plate and two rotational elasto-plastic springs at the end zone of the restrainer. Their stiffness and strength are investigated by mock-up experiments and analyses, and their evaluation methods are proposed.
  • 竹内徹,秦康, 松井良太
    日本建築学会構造系論文集 73 632 1875 - 1882 2008年10月 [査読有り][通常論文]
     
    H-section braces are widely used for seismic-proof elements in various kinds of structures. However, when they receive the cyclic loading beyond the expected seismic loads, they cause not only overall-buckling, but local buckling. It is known that such local buckling cause stress concentration within limited zones, and easily lead to the fracture of the member itself. Various hysteretic loop models for such braces have been proposed and used for timehistory analysis, however, it is not easy to predict the point of the fracture, their cumulative deformation capacity and energy dissipation capacity until the fracture. In this paper, cyclic loading tests on various H-section braces are carried out, and their fracture mechanism, relationship between the slenderness ratios and width-thickness ratios are researched. Their strain concentration mechanism is discussed through various analyses, followed by proposing easy evaluation method of their cumulative deformation capacity.
  • 竹内徹, 鈴木一弁, 松井良太, 小河利行
    日本建築学会構造系論文集 72 620 141 - 148 日本建築学会 2007年10月 [査読有り][通常論文]
     
    Tubular sections are commonly used for truss structures or diagonal braces, because they have higher moment-of-inertia comparing to H-sections or L-sections with the same area. However, their cumulative cyclic deformation capacity after buckling is known as quite small, because high strain concentration appears at local elbow buckling. To improve the performance of such members, the authors have proposed retrofit method to add outer tube and in-filled mortar in-between, as buckling restrainer. In this paper, cumulative cyclic deformation capacity of this member is researched by cyclic loading tests with various thickness ratios and strain amplitudes. Their strain concentration mechanism is also researched thorough various analyses, followed by proposing the concept of strain concentration index. The easy evaluation method for cumulative deformation capacity and energy dissipation capacity is proposed using this index.
  • An experimental study on cumulative cyclic deformation capacity of tubular braces with local buckling
    Kazuaki Suzuki, Toru Takeuchi, Ryota Matsui, Toshiyuki Ogawa
    Proceedings of 8th Pacific Structural Steel Conference - Steel Structures in Natural Hazards, PSSC 2007 1 57 - 62 2007年 
    Tubular sections are commonly used for truss structures or diagonal braces, because they have higher moment-of-inertia comparing to open cross-sections with the same area. However, their cumulative cyclic deformation capacities after buckling are known as quite small comparing to H-sections, because strain concentration occurs with local elbow buckling. For evaluating seismic performances of such structures, cumulative cyclic deformation capacity of braces before fracture is essential. In this paper, cumulative cyclic deformation capacity of tubular braces with local buckling is researched by cyclic loading tests with various slenderness ratios and thickness ratios. Their strain concentration mechanism is researched thorough various analyses.
  • 竹内徹, 鈴木一弁, 松井良太, 小河利行
    日本建築学会構造系論文集 71 608 143 - 150 日本建築学会 2006年10月 [査読有り][通常論文]
     
    Tubular sections are commonly used for truss structures or diagonal braces, because they have higher moment-of-inertia comparing to open cross-sections with the same area. However, their cumulative cyclic deformation capacities after buckling are known as quite small comparing to H-sections, because strain concentration occurs with local elbow buckling. For evaluating seismic performances of such structures, cumulative cyclic deformation capacity of braces before fracture is essential. In this paper, cumulative cyclic deformation capacity of tubular braces with local buckling is researched by cyclic loading tests with various slenderness ratios and thickness ratios. Their strain concentration mechanism is researched thorough various analyses, followed by proposing easy evaluation method of cumulative deformation capacity.

MISC

所属学協会

  • 日本鋼構造協会   日本建築学会   

共同研究・競争的資金等の研究課題

  • 日本学術振興会:科学研究費助成事業
    研究期間 : 2023年06月 -2026年03月 
    代表者 : 松井 良太, 岡崎 太一郎, 丸山 一平
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2020年04月 -2024年03月 
    代表者 : 岡崎 太一郎, 松井 良太, 岸田 明子, 松宮 智央, 高橋 典之, 藤原 淳, 長江 拓也
     
    鋼構造建築物の倒壊過程を実験的に解明する研究目的に沿って、国立研究開発法人防災科学技術研究所の大型耐震実験施設で、2020年11月から12月にかけて、縮尺1/2のパイロット試験体による振動台実験を実施した。防災科学技術研究所の兵庫耐震工学研究センターで、2020年12月に実施された日米共同実験に参加し、次世代型鋼構造システムを開発する研究を推進した。また、倒壊に至る鋼構造の非線形・動的挙動を追跡するコンピュータ解析技術を確立する研究目的に沿って、数値モデル化技術を種々検討した。一連の研究活動で得られた成果は、下記のとおりである。(1)模型実験の設計方法、柱や梁の降伏・破断挙動を測定するための計測・画像収録方法を確立し、2021年度に実施する本実験の準備を固めた。(2)複数の実験から得た、鋼構造架構の非線形動的応答に関する実データを、既往の大規模振動台実験のデータと合わせて、数値解析技術の検証を進めた。特に、破断を模擬するための現状のモデル化手法では、既往の重層架構実験で観察された、部材破断後の部材力再分配を正しく再現できないことを突き止め、今後の課題を特定した。減衰モデルの選択によって、ブレース付架構の応答変位や応答加速度が異なることに注目し、定量的な検討を進めた。(3)部材破断の再現方法を含めて、ブレース付鋼構造架構の解析手法に関する知見を蓄積し、現状のブレース付鋼構造架構が保有する耐震性能を検証した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2020年04月 -2023年03月 
    代表者 : 松井 良太, 岡崎 太一郎, 竹内 徹
     
    災害時における鋼構造物の被災事例は枚挙にいとまがなく,地震や風により崩壊した事例は年々増え続けている。人命を保護するため,局部座屈や部材破断などの不安定現象により,鋼構造物が倒壊しないよう設計手法が体系化されているが,事業継続性や居住快適性が重視されるなど,鋼構造物に対する要求は高度化しつつある。現行の設計体系で規定されていない鋼構造物の性能を迅速に評価できる信頼性の高い手法を,構造設計に携わる実務者が利用できれば,より冗長性の高い社会基盤を構築し得ると考えられる。本研究課題では,設計者の技量や熟練度に依らず,鋼構造物の限界性能を検証できる構造設計手法を提示することを目標としている。 数値解析プログラム整備のため,数値解析によりブレースおよび梁の耐力や塑性変形性能を検証した。梁については,これまで純鉄骨を中心として数値解析モデルを検討し,実構造物で多用される合成梁も含め検討する必要性を実感し,本研究課題に追加した。床スラブの仕様を変えた3種の合成梁に関して載荷実験を実施した。 ブレースの性能を整理したデータベースを構築するため,国内外における90件程度の既往の研究成果を調査し,502体の繰返し荷重を受けるブレース試験体の実績を抽出した。うち多数を占めたH形56体,中空円形62体,中空角形90体の断面を有する試験体のうち,建築基準法上,高い塑性変形能力があるランクに分類された試験体は1割から2割程度と寡少であることを確認した。同ブレースは実務上用いられる頻度は高く,構造性能を検証することが急務であることを再認識した。 構築したデータベースを参照し模型載荷実験では実績の少ない試験体として,断面や端部境界条件が異なる,有効細長比10から20の太短い試験体6体と,有効細長比30と80の試験体2体を製作した。載荷実験に向け実験場を整備し,効率的に模型載荷実験を進められるよう準備した。
  • コンクリ―トの経年変化を考慮したコンクリート充填構造における柱梁接合部パネルの弾塑性性状
    日本鉄鋼連盟:鋼構造研究・教育助成事業
    研究期間 : 2021年04月 -2023年03月
  • 鋼材ブレースの塑性変形性能を定量化した崩壊解析手法のための部材モデルの提案
    鹿島学術振興財団:研究助成
    研究期間 : 2020年04月 -2022年03月
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 竹内 徹, 松井 良太, 熊谷 知彦
     
    2016年熊本地震においてシステムトラス体育館の屋根部材が座屈・破断しその一部が落下する事故が複数発生した。システムトラスは我が国の体育館等に広く使用されている構造システムであるが,設計荷重に対し弾性設計されており,想定を超えた地震入力に対する耐力余裕度や崩壊挙動は明確になっていなかった。本研究では,部材実験、トラスユニット実験、部分架構振動台実験および解析によりシステムトラス置き屋根構造の崩壊メカニズムを明らかにした。また屋根全体の崩壊を防止する構法の検討や応答を制御する支承部へのエネルギー吸収要素の導入および設計法を提案し、地震直後の点群データ測定に基づく即時危険度判定手法の検討を行った。
  • 一次元有限要素によるH形断面梁端接合部の累積変形性能評価
    日本鉄鋼連盟:鋼構造研究・教育助成事業
    研究期間 : 2019年04月 -2021年03月
  • 日本学術振興会:科学研究費助成事業 若手研究(A)
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 松井 良太
     
    都市基盤上極めて重要性の高い施設の一つである火力発電プラントでは、重量物のボイラーを支持するために、他の構造形式では見られない高い軸力が鋼柱材に作用する。本研究では、この高い軸力が作用した状態で、繰返し水平力を受ける鋼柱材の耐力および変形性能について、部材実験より検証した。シェル要素などを用いた有限要素解析よりも相対的に少ない要素数で鋼柱材を構成した数理モデルである、一次元部材モデルにより、鋼柱材の挙動を再現できた。同モデルを地震応答解析プログラムに組み込み、鋼構造骨組の耐震性能を、検証できる枠組みを構築した。実大4層鋼構造骨組の振動台実験結果より、同プログラムの有効性を明らかにした。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 竹内 徹, 松井 良太, 薛 松濤, 熊谷 知彦
     
    鉄骨置屋根構造とはRC片持ち架構の上に鉄骨屋根が設置された形式の体育館等の空間構造を指す。東日本大震災ではこういった体育館の支承部が多くの損傷を受けた。支承部損傷の主原因のひとつとしてRC片持ち架構の構面外応答が指摘されているが、そのメカニズムや有効な改修・設計手法は確立していなかった。 本研究では、鉄骨屋根とRC片持ち架構の複雑な地震応答特性を明らかにするとともに、従来の滑り支承、ゴムパッドを用いた弾性支承、エネルギー吸収機能を持つ摩擦支承の実大実験、免震支承を導入した屋根架構の振動台実験を実施し、屋根架構の補強を不要とする改修・設計手法の提案、実用化および設計法の提示を行った。
  • 部材破断を考慮したブレース付鋼構造架構の振動台実験
    日本鉄鋼連盟:鋼構造研究・教育助成事業
    研究期間 : 2015年04月 -2016年03月
  • 日本学術振興会:科学研究費助成事業 若手研究(B)
    研究期間 : 2012年04月 -2015年03月 
    代表者 : 松井 良太
     
    本研究課題では,長周期地震動を受ける超高層建物の終局状態を評価するために,まず,数値解析により梁端接合部の累積変形性能について分析し,定量的な評価手法を提案した。また,H形断面梁端部に同評価手法を適用するために必要となる,繰返し荷重下の横補剛条件について,実験および数値解析より検証した。次に,同評価手法を拡張させるため,円形鋼管同士の分岐継手接合部を対象とした繰返し載荷実験を行った。最後に,申請者が提案してきたブレースおよび接合部破断の評価手法を組み込んだ時刻歴応答解析プログラムにより,建物の周期帯を考慮した地震動を用い,極大地震を受けた際の建物の耐震性能やフラジリティ曲線について分析した。
  • 日本学術振興会:科学研究費助成事業 特別研究員奨励費
    研究期間 : 2008年 -2010年 
    代表者 : 松井 良太
     
    最終年度となる平成22年度においては,昨年度において構成した三次元構造物を対象とした時刻歴応答解析手法を用いて,ブレース部材の破断を考慮した大地震時におけるブレース付ラーメン骨組のエネルギー吸収性能について分析した。その結果,ブレース部材の破断を考慮した場合のブレース付ラーメン骨組の時刻歴応答およびエネルギー吸収性能は,考慮していない場合に比較して大きな差異を生じることを示した。プレースの部材破断を考慮した場合,骨組の変位応答に大きな差異は見られないものの,柱梁の負担するエネルギー吸収量が大きく増大する例も見られた。本研究では,柱梁のエネルギー吸収性能については対象外としていたが,ブレースの部材破断に伴い柱梁の損傷が増大し,骨組全体のエネルギー吸収性能が大きく低下する可能性があることが確認された。 以上より,既存不適格建物の耐震補強に用いる鋼材ブレースが地震力を受けて破断に至るまでのエネルギー吸収性能を評価し,同ブレースを用いた骨組の大地震時における時刻歴応答およびエネルギー吸収性能を比較検証することが可能となった。これにより,既存不適格建物に想定以上の地震動が入力された場合に必要となる鋼材ブレースの補強量を,より適切に把握できるようになると考えられ,信頼性の高い耐震補強設計法の確立に貢献したものと考えられる。 以上の研究成果は国内外の学術会議および学術雑誌を通して発表しており,多数の研究者との意見交換および交流を密に図ることが出来た。


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