變斷面桁架圍束式挫屈束制支撐設計分析與試驗研究

A Study of BRBs using Varying Section Steel Truss Restrainers

10.6849/SE.202209_37(3).0002

陳律安(Lu-An Chen)；吳安傑(An-Chien Wu)；陳雋(Chun Chen)；蔡克銓(Keh-Chyuan Tsai)

挫屈束制支撐 ； 桁架圍束單元 ； 撓曲剛度 ； 剪力剛度 ； 挫屈強度 ； 有限元素分析 ； buckling-restrained brace ； truss-confined restrainer ； flexural rigidity ； shear rigidity ； buckling load ； finite element analysis

結構工程

37卷3期（2022 / 09 / 01）

27 - 47

繁體中文

挫屈束制支撐（buckling-restrained brace, BRB）能經濟且有效地提升結構勁度、強度與韌性消能行為，已廣泛運用於建築結構系統。桁架圍束式挫屈束制支撐（truss-confined BRB, TC-BRB）為新型BRB，特點在中央圍束鋼管外再配置由特定數量、方向及尺寸之桁架系統，並與中央鋼管共同構成圍束單元，提供所需之撓曲剛度。此種桁架圍束系統可使中央鋼管與內灌砂漿之斷面大幅下降，能減少自重但仍維持設計強度；此優勢特別利於長跨與高軸力BRB之應用。本研究擴充、改良與簡化過去研究的理論模型與設計方法，提出變斷面桁架圍束系統及中央鋼管等效剛度的精確計算方法，利用能量法評估圍束單元彈性挫屈強度，並提供簡化計算方式。為進一步驗證分析理論，本研究新增規劃兩組1／3縮尺之變斷面TC-BRB試體，設計長度與強度分別約為6.3米與90噸，採用國震中心多軸向試驗系統進行反覆載重試驗。藉由四組試驗結果提出圍束單元彈性挫屈強度與整體TC-BRB壓力強度計算方法，並建議工程實務應用時可採用的設計參數。此外，本研究提出一套有限元素模型分析方法，能有效模擬弦桿殘餘應力效應及BRB壓拉強度差異現象，驗證圍束單元彈性挫屈強度理論分析的可靠度，並可有效模擬TC-BRB實際受力變形反應。

Buckling-restrained braces (BRBs) can effectively improve the stiffness, strength, ductility, and energy dissipation capacity of building structures. Recently, a novel type of BRB called truss-confined BRB (TC-BRB) has been investigated. The feature of the TC-BRB is attaching an additional truss system outside the central steel casing. The truss system is composed of several steel open-web truss frames thereby providing the overall restraining rigidity, reducing the steel casing section size and infilled mortar. The overall self-weight is reduced as compared to the conventional BRB, especially in the cases of long-span and large load-carrying BRB applications. This study extends and improves the stability assessment methods of the TC-BRB investigated previously. The equivalent flexural rigidity and shear rigidity of varying-section truss confining system are re-examined first. The method of computing the effective shear area of central casing is developed. The results are integrated into the calculations of elastic buckling strength of the restraining system. A simplified computing method is also proposed. Two additional 1/3-scaled specimens each of about 6.3m long and 90tf (853kN) yield strength were designed and tested in the MATS facility in NCREE. Considering tests results of four specimens of similar size and capacity in the previous and this studies, the relationship between the elastic buckling strength of restrainer and the ultimate compressive strength of entire TC-BRB is constructed. The required design parameters are provided for practical applications. In addition, a numerical modeling procedure which can effectively simulate the effects of the BRB compressive over-strength and the residual stresses in the chord members is introduced. Analytical results indicated that the proposed calculations in the restrainer's elastic buckling strength are reliable and the specimens' hysteresis behavior can be captured satisfactorily.

1. 陳雋,林昱成,吳安傑,陳律安,蔡克銓(2021)。長跨桁架圍束式挫屈束制支撐之研究。結構工程，36(2)，5-50。
   連結：
2. Abaqus(2013).Abaqus, 2013, Abaqus Version 6.13 Documentation. Dassault Systemes Simulia Corporation, Providence, Rhode Island..
3. American Institute of Steel Construction=AISC(2016).Seismic Provisions for Structural Steel Buildings (AISC 341-16).Chicago, Illinois:AISC.
4. Chuang, MC,Tsai, KC,Lin, PC,Wu, AC(2015).Critical limit states in seismic buckling-restrained brace and connection designs.Earthquake Engineering & Structural Dynamics,44(10),1559-1579.
5. Goodno, BJ,Gere, JM(2017).Mechanics of Materials.Boston, Massachusetts:Cengage Learning.
6. Guo, YL,Zhou, P,Wang, MZ,Pi, YL,Bradford, MA(2017).Numerical studies of cyclic behavior and design suggestions on triple-truss-confined buckling-restrained braces.Engineering Structures,146,1-17.
7. Guo, YL,Zhou, P,Wang, MZ,Pi, YL,Bradford, MA,Tong, JZ(2017).Experimental and numerical studies of hysteretic response of triple-truss-confined buckling-restrained braces.Engineering Structures,148,157-174.
8. Li, XH,Sun, Q,Zhang, XH(2021).Identification of combined hardening model parameters by considering pre-tensile stress for 2024-T3 aluminum alloy.Materials Today Communication,26,102065.
9. Lin, PC,Tsai, KC,Chang, CA,Hsiao, YY,Wu, AC(2016).Seismic design and testing of buckling-restrained braces with a thin profile.Earthquake Engineering & Structural Dynamics,45(3),339-358.
10. Lin, TH,Chen, PC,Lin, KC(2017).The multiaxial testing system for earthquake engineering researches.Earthquakes and Structures,13(2),165-176.
11. McGuire, W,Gallagher, RH,Ziemian, RD(2000).Matrix Structural Analysis.New York:John Wiley & Sons, Inc..
12. Shanley, FR(1957).Strength of Materials.New York:McGraw-Hill.
13. Takeuchi, T,Ozaki, H,Matsui, R,Sutcu, F(2014).Out-of-plane stability of bucklingrestrained braces including moment transfer capacity.Earthquake Engineering & Structural Dynamics,43(6),851-869.
14. Timoshenko, SP,Gere, JM(1963).Theory of Elastic Stability.New York:McGraw-Hill.
15. Tsai, KC,Wu, AC,Wei, CY,Lin, PC,Chuang, MC,Yu, YJ(2014).Welded end-slot connection and debonding layers for buckling-restrained braces.Earthquake Engineering & Structural Dynamics,43(12),1785-1807.
16. Wu, AC,Lin, PC,Tsai, KC(2014).High-mode buckling responses of buckling-restrained brace core plates.Earthquake Engineering & Structural Dynamics,43(3),375-393.
17. 吳安傑,林保均,莊明介,蔡克銓(2015)。挫屈束制支撐構架設計概要與工程應用。結構工程，30(1)，11-33。
18. 吳安傑,林保均,蔡克銓(2013)。挫屈束制支撐核心鋼板高模態挫屈行為研究。結構工程，28(1)，23-42。
19. 林德宏,林克強,蔡克銓(2012)。國家地震工程研究中心多自由度多功能構件試驗系統設置與應用。結構工程，27(3)，87-107。
20. 蔡克銓,吳安傑,林保均,魏志毓,莊明介(2012)。槽接式挫屈束制支撐與脫層材性能研究。結構工程，27(3)，29-59。