【正文】 es from buckling. Some key issues of BRB configurations, such as gap and debonding processing between core braces and encasing members, contraction allowance in BRBs and necessary clearances between restraining panels and surrounding frames, BRB projection stiffening approaches to prevent it from buckling, are also described. Based on initial deflections of core braces, both stiffness and strength requirements of encasing member to prevent buckling of core brace are given. Applications for both new highrise steel buildings and the seismic retrofit of existing buildings show good prospects of using BRBs. 169。 2004 Elsevier Ltd. All rights reserved.Keywords: Steel frame。 Damper。 4. Separation unit between brace and bucklingrestraining units, which ensures the brace can slide freely inside the bucklingrestraining unit and that transverse expansion of the brace can take place when the brace yields in pression. This typically requires some debonding material to be employed as a separation unit. Otherwise, a gap should be kept between the two units. This paper introduces the research and developments of various types of BRBs with different configurations in Asia, especially in Japan in the past few decades. Theories and experiments for the conditions to prevent steel braces from buckling are illustrated. Some key issues of BRB configurations and requirements of stiffness and strength of encasing member are also described. Applications for both new highrise steel buildings and the seismic retrofit of existing buildings show good prospects of using BRBs.2. Development of BRBs. History of BRBsResearch on BRBs was first carried out by Yoshino et al. [1]. They tested cyclicallytwo specimens that they called “Shear wall with braces”, consisting of a flat steel plate encased by reinforced concrete panels with some debonding materials between them. One has a clearance of 15 mm between the panel lateral sides and the surrounding panel whilst the other was not provided with such spacing. The former exhibits higher deformation and energy dissipation capacity than the latter.Wakabayashi et al. conducted pioneering thorough research on BRBs [2,3]. They developed a system in which braces made of steel flat plates were encased by reinforced concrete panels with an unbonded layer between them. They found that the process of achieving debonding on the brace’s surface was very important to make the brace–panel system to satisfy the condition that only the brace resists horizontal loading while the concrete panel serves only to prevent the brace from buckling. A multistep experimental plan was carried out, which consisted of (1) testing of debonding materials to explore unbonded effects。本文介紹了亞洲特別是日本的各種類型防屈曲支撐的研究和發(fā)展。給出了核心支撐在有初始撓度下防止核心支撐屈曲的強(qiáng)度和剛度要求。關(guān)鍵詞：鋼框架。阻尼器。如果要阻止鋼支撐的屈曲，保證支撐在拉伸和壓縮下具有相同的強(qiáng)度，支撐吸收的能量將顯著增加，遲滯行為減弱。如圖2所示，防屈曲支撐通常包括以下四個(gè)部分：1，軸向力承載單位（支撐）。這通常需要一些剝離材料作為分離單元。對(duì)防屈曲支撐的配置和外包單元對(duì)剛度和強(qiáng)度要求的一些關(guān)鍵問(wèn)題也有所說(shuō)明。一種橫向面板兩側(cè)與周圍的面板有15mm的距離，而其他的則沒有間隙。他們發(fā)現(xiàn)，實(shí)現(xiàn)對(duì)支撐的表面剝離過(guò)程非常重要，只有使支撐板系統(tǒng)滿足這個(gè)條件，支撐抵抗水平荷載時(shí)混凝土面板才會(huì)防止支撐失穩(wěn)。該涂層的硅樹脂的環(huán)氧樹脂層頂部剝離方法是使用下面的測(cè)試。為了驗(yàn)證遲滯行為，對(duì)十四的X形和由鋼筋混凝土板包裹X形支撐構(gòu)件在循環(huán)荷載下進(jìn)行了測(cè)試。無(wú)粘結(jié)支撐沿支撐軸的應(yīng)變分布均勻，這表明了無(wú)粘結(jié)支撐的效果。由木村等人進(jìn)行的第一次測(cè)試鋼支撐包裹的是砂漿充填鋼管。在他們隨后的研究[5]，四個(gè)全面構(gòu)件，其中兩個(gè)有支撐與周圍之間灌一些砂漿，進(jìn)行了測(cè)試循環(huán)。藤本等[9,10]延長(zhǎng)木村和武田研究了鋼芯支撐被涂剝離材料和砂漿，充填方鋼管約束。圖6給出了這兩種類型的防屈曲支撐的照片。圖7（c）給出了由鋼纖維鋼筋混凝土包裹的縱橫交錯(cuò)截面鋼支撐的[19]。在此配置中，內(nèi)管是提供對(duì)橫向變形的約束，同時(shí)外管是一個(gè)[23,24]可以抵抗軸向力的構(gòu)件。圖7（J）顯示了鋼板螺栓將板[31]約束起來(lái)。3. 防屈曲支撐分析的一些要點(diǎn)如前所述，核心支撐和約束單元之間的間隙保證了支撐在收到壓縮可以在約束單元內(nèi)自由的進(jìn)行橫向擴(kuò)展，這是是非常重要的。因此，約束單元的應(yīng)該同時(shí)考慮。通過(guò)安裝了無(wú)粘結(jié)支撐可以提高建筑物的抗震性能，整個(gè)臺(tái)北縣行政大樓（TCAB）應(yīng)用了一些新的設(shè)計(jì)和改造項(xiàng)目，在臺(tái)灣選擇了雙T型雙管防屈曲這次很難過(guò)提高建筑物的抗震性能[37]。還說(shuō)明了防屈曲鋼支撐的理論和實(shí)驗(yàn)。新建的