本文選題：鋼筋混凝土框架結(jié)構(gòu) + 屈曲約束支撐(BRB)�。� 參考：《中國建筑科學(xué)研究院》2017年碩士論文

【摘要】：普通支撐受壓會產(chǎn)生屈曲現(xiàn)象,當(dāng)支撐受壓屈曲后,剛度和承載力急劇降低。當(dāng)支撐由壓曲狀態(tài)逐漸變至受拉狀態(tài)時,支撐的內(nèi)力以及剛度接近為零。因而普通支撐在反復(fù)荷載作用下滯回性能較差。屈曲約束支撐又稱防屈曲支撐或BRB(Buckling restrained brace)是新型的耗能支撐,與傳統(tǒng)支撐最大的區(qū)別是BRB的主要耗能構(gòu)件,即內(nèi)核單元外圍有約束單元的限制,使其在軸向壓力的作用下,發(fā)生全截面屈服之前不會發(fā)生屈曲,從而避免了傳統(tǒng)支撐受壓時容易失穩(wěn)的問題。BRB有良好的延性和滯回性能,在彈性階段工作時,就如同普通支撐可為結(jié)構(gòu)提供很大的抗側(cè)剛度,可用于抵抗小震以及風(fēng)荷載的作用。在彈塑性階段工作時,變形能力強、滯回性能好,就如同一個性能優(yōu)良的耗能阻尼器,可用于結(jié)構(gòu)抵御強烈地震作用,提高結(jié)構(gòu)的抗倒塌性能。安裝屈曲約束支撐(BRB)的框架結(jié)構(gòu)(以下簡稱BRB框架結(jié)構(gòu))可以減少設(shè)計配筋,那么按多遇地震設(shè)計后能否滿足“大震不倒”的抗震設(shè)防要求自然成為研究者關(guān)注的一個問題。本文用數(shù)值模擬的方法分析不同構(gòu)件尺寸,不同高度,不同空間布置(包括按6度、7度、8度、9度分別設(shè)計的三層框架、五層框架結(jié)構(gòu)以及按所在烈度設(shè)計的其余四個框架結(jié)構(gòu))的框架結(jié)構(gòu)和BRB框架結(jié)構(gòu)在罕遇地震、極罕遇地震下的抗震性能,具體體現(xiàn)在結(jié)構(gòu)的層間變形,基底剪力,塑性鉸數(shù)量和發(fā)育情況以及豎向構(gòu)件耗能等。通過比較BRB框架結(jié)構(gòu)和框架結(jié)構(gòu)的有限元計算結(jié)果,本文認(rèn)為:(1)得益于BRB卓越的耗能能力,BRB框架結(jié)構(gòu)在罕遇地震和極罕遇地震作用下,結(jié)構(gòu)地震反應(yīng)減弱,結(jié)構(gòu)完全可以滿足“大震不倒”的抗震設(shè)防要求。(2)框架結(jié)構(gòu)和BRB框架結(jié)構(gòu)在罕遇地震作用下層間位移角均滿足規(guī)范要求。極罕遇地震作用下,框架結(jié)構(gòu)6度時位移角最大值均小于1/50,7度時位移角最大值已十分接近1/50(部分地震波計算層間位移角最大值大于1/50),8度、9度時部分結(jié)構(gòu)位移角最大值已大于1/50;各烈度BRB框架結(jié)構(gòu)層間位移角均滿足規(guī)范1/50限值要求。BRB框架結(jié)構(gòu)有較高的安全儲備,可預(yù)防突發(fā)性超強烈地震作用下結(jié)構(gòu)的倒塌破壞。美國學(xué)者在上世紀(jì)90年代初率先提出了基于性能的抗震設(shè)計思想。在這一思想的指導(dǎo)下,許多學(xué)者提出了他們基于位移的抗震設(shè)計方法。本文在他們研究的基礎(chǔ)上,由相關(guān)基本假定和一些既定的理論研究結(jié)果推導(dǎo)出配箍特征值的理論計算公式。將有限元軟件模擬得到的不同BRB框架結(jié)構(gòu)的最大層間位移角均值帶入配箍特征值公式,從而得到BRB框架結(jié)構(gòu)的配箍特征值建議值。
[Abstract]:The buckling of common braces is induced by compression, and the stiffness and bearing capacity decrease sharply after buckling. The internal force and stiffness of the bracing are close to zero when the buckling state is gradually changed to the tensile state. Therefore, the hysteretic behavior of common braces under repeated load is poor. Buckling restrained braces, also called buckling braces or BRB(Buckling restrained brace, are a new type of energy dissipation support. The biggest difference from traditional braces is that the main energy dissipation components of BRB, that is, the core element is limited by the constraint element, make it under the action of axial pressure. There will be no buckling before the full section yield occurs, thus avoiding the problem of instability of traditional braces under compression. BRB has good ductility and hysteretic performance. Just as ordinary braces can provide large lateral stiffness for structures, they can be used to resist small earthquakes and wind loads. In the elastic-plastic stage, the deformation ability is strong, the hysteretic performance is good, just like a good energy dissipation damper, it can be used to resist the strong earthquake action of the structure and improve the collapse resistance of the structure. The frame structure with buckling constraint bracing (hereinafter referred to as BRB frame structure) can reduce the design reinforcement, so whether or not the seismic fortification requirement of "big earthquake can not collapse" can be satisfied after frequent earthquake design has become a problem that researchers pay attention to naturally. In this paper, the numerical simulation method is used to analyze the three story frames with different dimensions, different heights and different spatial arrangements (including three layers designed according to 6 degrees, 7 degrees, 8 degrees and 9 degrees, respectively). The seismic behavior of the five-story frame structure and the other four frame structures designed according to the intensity of the structure) and the BRB frame structure under rare and extremely rare earthquakes are embodied in the interstory deformation of the structure and the shear force of the base. The number and development of plastic hinges and the energy consumption of vertical components. By comparing the finite element results of BRB frame structure with that of frame structure, it is concluded in this paper that the structural seismic response of BRB frame structure is weakened under rare and extremely rare earthquake due to the excellent energy dissipation capacity of BRB. The structure can completely meet the requirements of seismic fortification of "strong earthquake not collapsing". 2) frame structure and BRB frame structure can meet the requirements of code for displacement angle between the lower layer of rare earthquake action. Under the action of extremely rare earthquakes, When the maximum displacement angle of frame structure is less than 1 / 50 / 7 degree, the maximum displacement angle of frame structure is very close to 1 / 50 (the maximum displacement angle of partial seismic wave is greater than 1 / 50 / 9 degree and the maximum value of displacement angle of partial seismic wave is more than 1 / 50 when the maximum value of displacement angle is more than 1 / 50). The inter-story displacement angle of BRB frame structure meets the limit value of 1 / 50 of code. BRB frame structure has a high safety reserve. It can prevent the structure from collapsing and destroying under the action of sudden super strong earthquake. American scholars first put forward the idea of performance-based seismic design in the early 1990s. Under the guidance of this idea, many scholars put forward their displacement-based seismic design methods. On the basis of their research, this paper deduces the theoretical calculation formula of the eigenvalue of collars based on the relevant basic assumptions and some established theoretical results. The maximum interstory displacement angle of different BRB frame structures is introduced into the hoop eigenvalue formula by finite element simulation, and the suggested hoop eigenvalue of BRB frame structure is obtained.
【學(xué)位授予單位】：中國建筑科學(xué)研究院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU352.11
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本文編號：1979161