外包钢加固RC柱二次受力下的耐火性能有限元分析
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摘要
建立了外包钢加固钢筋混凝土柱(ASSRC)二次受力下的耐火性能分析有限元模型,采用课题组完成的2根外包钢加固RC柱抗火试验数据,验证了模型的合理性。应用验证后的模型,分析了加固前后荷载分配比、荷载比、偏心率和配筋率对外包钢加固RC柱耐火性能的影响。二次受力情况下的分析结果表明:加固前后荷载分配比越大,柱顶初始轴向位移越大,轴向位移差随着受火时间增加而减小;当荷载比较小时,二次受力不会对柱的耐火极限产生影响,但荷载比较大时,加固前后荷载分配比越大,耐火极限越大;荷载比对柱抗火性能影响显著,荷载比越大,加固柱的柱顶轴向位移越大,耐火极限越小;偏心率越大,配筋率越小,承载力提高系数越高,耐火极限越小。
To research the fire resistance behavior of the fire resistance of angle steel strengthened reinforced concrete(RC) columns under twice loading, in this paper the finite element simulation model is built, the data of two angle steel strengthened RC columns tested for fire resistance by our research group is used to verify the ra-tionality of the model, and the influence of the distribution ratio of load between before and after strengthened,the load ratio, eccentricity ratio of the load and reinforcement ratio to the fire resistance behavior of angle steel strengthened RC columns is considered by verification model. The result of finite element analysis under twice load shows that the larger distribution ratio of load, the larger initial axial displacement of column will be; when the load ratio is small, the twice loading has no effect on fire resistance of column; when load ratio is large, the larger distribution ratio of load, the more fire resistance will be; the load ratio is the most significant parameter,the higher the load ratio, the lager axial displacement of column and less fire resistance will be; the higher ec-centricity ratio of the load and larger reinforcement ratio, the higher coefficient of improvement of ultimate load capacity will be, and lead to less fire resistance.
To research the fire resistance behavior of the fire resistance of angle steel strengthened reinforced concrete(RC) columns under twice loading, in this paper the finite element simulation model is built, the data of two angle steel strengthened RC columns tested for fire resistance by our research group is used to verify the ra-tionality of the model, and the influence of the distribution ratio of load between before and after strengthened,the load ratio, eccentricity ratio of the load and reinforcement ratio to the fire resistance behavior of angle steel strengthened RC columns is considered by verification model. The result of finite element analysis under twice load shows that the larger distribution ratio of load, the larger initial axial displacement of column will be; when the load ratio is small, the twice loading has no effect on fire resistance of column; when load ratio is large, the larger distribution ratio of load, the more fire resistance will be; the load ratio is the most significant parameter,the higher the load ratio, the lager axial displacement of column and less fire resistance will be; the higher ec-centricity ratio of the load and larger reinforcement ratio, the higher coefficient of improvement of ultimate load capacity will be, and lead to less fire resistance.
引文
[1]MARTIN VILD,MIROSLAV BAJER.Strengthening under Load:The Effect of Preload Magnitudes[J].Procedia Engineering,2016,161:343-348.
[2]YI LIU,LIAM GANNON.Experimental behavior and strength of steel beams strengthened while under load[J].Journal of Constructional Steel Research,2009,65(6):1346-1354.
[3]PENG GAO,XIANGLIN GU,AYMAN S MOSALLAM.Flexural behavior of preloaded reinforced concrete beams strengthened by prestressed CFRP laminates[J].Composite Structures,2016,157(12):33-50.
[4]梁正洪,杨俊杰.CFRP加固大偏压RC柱二次受力时的机理分析[J].浙江工业大学学报,2010,38(4):458-462.
[5]吴波,万志军.碳纤维布抗弯加固钢筋混凝土梁的耐火性能试验[J].华南理工大学学报(自然科学版),2009,37(8):76-82.
[6]吴波,万志军,王帆.碳纤维布抗弯加固钢筋混凝土梁的耐火极限分析[J].工程抗震与加固改造,2008,30(2):101-108.
[7]高皖扬,胡克旭,陆洲导.CFRP加固钢筋混凝土梁耐火性能试验研究[J].土木工程学报,2010,43(3):15-23.
[8]周立人.角钢加固钢筋混凝土梁、柱构件抗火性能试验研究[D].苏州:苏州科技大学,2016.
[9]LIE T T,DENHAM E M A.Factors affecting the fire resistance of circular hollow steel columns filled with bar-reinforced concrete[R].NRC-CNRC,Canada,1993.
[10]LIE T T,IRWIN R J.Fire resistance of rectangular steel columns filled with bar-reinforced concrete[J].Journal of structural engineering,1995,121(5):797-805.
[11]European Committee for Standardization.Eurocode 3:Design of steel structures:EN 1993-1-2[S].Brussels,1993.
[2]YI LIU,LIAM GANNON.Experimental behavior and strength of steel beams strengthened while under load[J].Journal of Constructional Steel Research,2009,65(6):1346-1354.
[3]PENG GAO,XIANGLIN GU,AYMAN S MOSALLAM.Flexural behavior of preloaded reinforced concrete beams strengthened by prestressed CFRP laminates[J].Composite Structures,2016,157(12):33-50.
[4]梁正洪,杨俊杰.CFRP加固大偏压RC柱二次受力时的机理分析[J].浙江工业大学学报,2010,38(4):458-462.
[5]吴波,万志军.碳纤维布抗弯加固钢筋混凝土梁的耐火性能试验[J].华南理工大学学报(自然科学版),2009,37(8):76-82.
[6]吴波,万志军,王帆.碳纤维布抗弯加固钢筋混凝土梁的耐火极限分析[J].工程抗震与加固改造,2008,30(2):101-108.
[7]高皖扬,胡克旭,陆洲导.CFRP加固钢筋混凝土梁耐火性能试验研究[J].土木工程学报,2010,43(3):15-23.
[8]周立人.角钢加固钢筋混凝土梁、柱构件抗火性能试验研究[D].苏州:苏州科技大学,2016.
[9]LIE T T,DENHAM E M A.Factors affecting the fire resistance of circular hollow steel columns filled with bar-reinforced concrete[R].NRC-CNRC,Canada,1993.
[10]LIE T T,IRWIN R J.Fire resistance of rectangular steel columns filled with bar-reinforced concrete[J].Journal of structural engineering,1995,121(5):797-805.
[11]European Committee for Standardization.Eurocode 3:Design of steel structures:EN 1993-1-2[S].Brussels,1993.