對(duì)位于9 度區(qū)的某高層鋼結(jié)構(gòu)住宅,分別采用中美歐三種抗震設(shè)計(jì)規(guī)范來(lái)進(jìn)行設(shè)計(jì),比較不同規(guī)范下的基底剪力、層間位移角、用鋼量等指標(biāo)。結(jié)果表明:三種規(guī)范在相同地震動(dòng)參數(shù)下,美標(biāo)與歐標(biāo)對(duì)應(yīng)的基底 剪力要低于中國(guó)規(guī)范模型對(duì)應(yīng)結(jié)果,同時(shí)美歐對(duì)層間位移角的控制較松,最終在美標(biāo)設(shè)計(jì)下用鋼量最省,歐標(biāo)設(shè)計(jì)下其次,中國(guó)規(guī)范模型用鋼量最大。根據(jù)動(dòng)力彈塑性分析結(jié)果,中國(guó)規(guī)范模型的彈塑性層間位移角最小,美歐模型的彈塑性層間位移角偏大,三個(gè)模型的最大彈塑性層間角均能滿足1/50 限值要求。
查看更多為研究采用防火裝飾一體化構(gòu)造的鋼梁在火災(zāi)下的溫度場(chǎng)和承載力,通過(guò)基于ANSYS 軟件建立的分析模型對(duì)不同截面尺寸和不同耐火極限的鋼梁進(jìn)行抗火性能研究,并給出了計(jì)算鋼梁承載力的簡(jiǎn)化公式,公式計(jì)算結(jié)果與有限元結(jié)果吻合情況較好。
查看更多Experimental study is conducted on the behavior of CFNRST members subjected to combined compression and uniaxial bending about the weak axis. Eleven specimens were fabricated considering the variation of key parameters including the slenderness, the width/height ratio of cross-section and eccentricity of compression. Comparisons are made between the predictions of representative solutions of design codes and the test results to examine their capacity for predicting the ultimate load of CFNRST members. New solutions with modifications on two existing solutions are proposed for the ultimate load of CFNRST members subjected to combined compression and uniaxial bending. Good agreements are achieved between the predictions of the proposed solutions and test results.
查看更多In this paper, experimental results are presented involving 24 specimens of CFNRST stub columns subjected to axial compression. The axial resistant behavior of CFNRST columns is investigated concerning the effects of key parameters including: (a) cross-sectional aspect ratio, (b) confining factor, and (c) width-to-thickness ratio of wider side of steel tube. By analyzing the observed and measured test results, the failure modes, ductility performance, strength enhancement effect and residual resistance of the specimens are discussed in detail. Moreover, 173 test results of CFRST stub columns under axial compression reported in the literature are collected and compared with the test results of this study; hence, the effect of extremely large crosssectional aspect ratio on the behavior of CFRST columns is presented. Finally, typical equations specified in design codes are examined to reveal their validity in predicting the ultimate axial resistance of both CFNRSTs and ordinary CFRSTs.
查看更多針對(duì)鋼結(jié)構(gòu)住宅建筑中柱子寬度日趨減小的趨勢(shì),提出了柱內(nèi)無(wú)隔板的矩形鋼管混凝土柱-H形鋼梁外頂板式節(jié)點(diǎn)。對(duì)7個(gè)新型節(jié)點(diǎn)試件進(jìn)行擬靜力試驗(yàn),變化參數(shù)有鋼梁截面、頂板厚度和頂板長(zhǎng)邊高度。試驗(yàn)主要研究了節(jié)點(diǎn)的破壞模式、滯回曲線、骨架曲線、承載力、剛度退化、強(qiáng)度退化、延性和耗能能力等抗震性能。試驗(yàn)結(jié)果表明:外頂板式節(jié)點(diǎn)共有梁翼緣受拉破壞、梁翼緣與頂板連接焊縫破壞、頂板與柱連接處的柱壁破壞三種破壞模式。節(jié)點(diǎn)延性系數(shù)為2.17~3.67,等效粘滯阻尼系數(shù)在0.2~0.3之間,極限位移角平均值為1/49,節(jié)點(diǎn)抗震性能滿足“強(qiáng)節(jié)點(diǎn)弱構(gòu)件”要求。增大外頂板的厚度或長(zhǎng)邊高度可提高節(jié)點(diǎn)承載力,鋼梁翼緣、翼緣和頂板連接焊縫或柱壁的過(guò)早開(kāi)裂會(huì)降低節(jié)點(diǎn)延性和耗能能力。最后提出在驗(yàn)算柱壁和連接焊縫極限承載力時(shí),節(jié)點(diǎn)連接系數(shù)應(yīng)取1.4;另外可采取梁端翼緣加強(qiáng)或削弱措施,以保證外頂板式節(jié)點(diǎn)具有足夠的塑性變形能力。
查看更多與混凝土及砌體結(jié)構(gòu)相比,鋼結(jié)構(gòu)雖然具有輕質(zhì)高強(qiáng)、抗震性能好等優(yōu)點(diǎn),但在火災(zāi)高溫下,其屈服強(qiáng)度、承載力會(huì)迅速降低。目前市場(chǎng)上主流的非膨脹型鋼結(jié)構(gòu)防火涂料表面粗糙、結(jié)構(gòu)疏松,無(wú)法滿足室內(nèi)鋼構(gòu)件的裝飾需求。本文提出了一種兼具防火與裝飾性能的石膏基防火材料,通過(guò)等效導(dǎo)熱系數(shù)試驗(yàn)和數(shù)值模擬對(duì)其防火性能進(jìn)行了評(píng)估并用于鋼結(jié)構(gòu)防火設(shè)計(jì)中,同時(shí)通過(guò)試驗(yàn)確定了一種性能可靠、經(jīng)濟(jì)性好的配套界面劑。
查看更多通過(guò)對(duì)ETABS軟件進(jìn)行二次開(kāi)發(fā),給出《鋼結(jié)構(gòu)設(shè)計(jì)標(biāo)準(zhǔn)》(GB50017-2017)直接分析設(shè)計(jì)法在ETABS軟件中的實(shí)現(xiàn)方式。在此基礎(chǔ)上,以山東某高層住宅項(xiàng)目采用的隱式框架—支撐結(jié)構(gòu)體系為例,采用考慮結(jié)構(gòu)整體初始幾何缺陷和構(gòu)件初始缺陷的動(dòng)力彈塑性分析方法,分析該結(jié)構(gòu)在大震下的動(dòng)力響應(yīng)和兩種缺陷對(duì)結(jié)構(gòu)抗震性能的影響。分析結(jié)果表明:罕遇地震作用下,有無(wú)考慮缺陷和二階效應(yīng)時(shí)得到的結(jié)構(gòu)最大層間位移角均未超過(guò)1/50限值,支撐起到了第一道抗震防線的作用,框架柱保持彈性,滿足“強(qiáng)框架,弱支撐”的設(shè)計(jì)要求??紤]缺陷和二階效應(yīng)會(huì)使結(jié)構(gòu)最大層間位移角有所增加,根據(jù)結(jié)構(gòu)二階效應(yīng)系數(shù)和延性系數(shù)可近似估算二階效應(yīng)對(duì)最大層間位移角的放大系數(shù)。對(duì)于高延性結(jié)構(gòu),在進(jìn)行動(dòng)力彈塑性分析時(shí),應(yīng)考慮缺陷和二階效應(yīng)對(duì)結(jié)構(gòu)抗震性能的影響。
查看更多為了研究分離式豎向加勁板鋼管混凝土柱- 梁節(jié)點(diǎn)的抗震性能, 對(duì)7 個(gè)節(jié)點(diǎn)試件進(jìn)行了在柱頂施加恒定軸壓力、梁端施加往復(fù)荷載的試驗(yàn)。通過(guò)對(duì)試驗(yàn)數(shù)據(jù)分析, 得到了各個(gè)試件的荷載- 位移曲線、骨架曲線、應(yīng)變曲線、強(qiáng)度和剛度退化規(guī)律、延性等結(jié)果。試驗(yàn)觀測(cè)到節(jié)點(diǎn)發(fā)生3 種破壞模式: 梁翼緣在加勁板短邊附近受拉破壞; 梁翼緣和加勁板間焊縫受剪破壞; 與加勁板連接處的鋼管壁受拉破壞。在屈服線理論的基礎(chǔ)上, 提出了與加勁板連接處鋼管壁受拉破壞模式下的塑性機(jī)構(gòu)模型。根據(jù)虛功原理推導(dǎo)出了該模式下的屈服荷載計(jì)算公式, 計(jì)算公式與試驗(yàn)結(jié)果吻合較好。將推導(dǎo)出的公式與典型的3 種破壞模式計(jì)算公式相組合, 可以準(zhǔn)確地預(yù)測(cè)節(jié)點(diǎn)最終破壞模式。
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