防火板保护双跨框支墙梁受火性能研究
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摘要
采用ABAQUS分别对托梁有无防火保护的双跨框支墙梁砌体结构的底框进行了受火数值分析,对二者的温度场、耐火极限、托梁变形、转换柱内力和托梁端部受弯载荷比进行研究。结果表明:框支托梁是框支墙梁转换层耐火极限的关键构件;框支托梁达到承载力的耐火极限时,两跨框支托梁的挠度与跨度比相等;托梁进行防火板保护后,转换层转换柱底部反向弯矩增幅较大,转换柱配筋较小时,需对其进行受弯承载力验算;随着梁端受弯载荷比的增加,框支墙梁砌体结构的两种耐火极限急剧减小,墙梁顶面荷载的大小是其耐火极限的重要影响因素之一。
The software ABAQUS is used to numerical analyze the fire resistance of double-span frame-supported wall-beam masonry structure with and without fire protection. The temperature, fire resistance limit, beam deformation, column's internal force and beam end bending bearing capacity ratio are investigated. Results obtained from this study are as follows: Frame-supported beam is the key component of fire resistance limit. When the frame supported beamachieves the fire resistance limit of bearing capacity, the deflection of the two spans is equal to the span ratio.After the bracket is protected by fire-proof plate, the reverse bending moment at the bottom of the transfer column increases greatly, and when the reinforcement of the transfer column is small, it is necessary to check the flexural bearing capacity of the transfer column.With the increase of the bending load ratio at the end of the beam,the two fire resistance limits of frame-supported wall-beam masonry structure decrease sharply, and the magnitude of the top load of the wall-beam is one of the important factors affecting the fire resistance limits.
The software ABAQUS is used to numerical analyze the fire resistance of double-span frame-supported wall-beam masonry structure with and without fire protection. The temperature, fire resistance limit, beam deformation, column's internal force and beam end bending bearing capacity ratio are investigated. Results obtained from this study are as follows: Frame-supported beam is the key component of fire resistance limit. When the frame supported beamachieves the fire resistance limit of bearing capacity, the deflection of the two spans is equal to the span ratio.After the bracket is protected by fire-proof plate, the reverse bending moment at the bottom of the transfer column increases greatly, and when the reinforcement of the transfer column is small, it is necessary to check the flexural bearing capacity of the transfer column.With the increase of the bending load ratio at the end of the beam,the two fire resistance limits of frame-supported wall-beam masonry structure decrease sharply, and the magnitude of the top load of the wall-beam is one of the important factors affecting the fire resistance limits.
引文
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[5]杨卫忠.砌体受压本构关系模型[J].建筑结构,2008,(10):80-82.
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[7]张耕源,邱仓虎,白连平,等.某车辆段现浇整体式梁板耐火性能研究[J].消防科学与技术,2018,37(9):1181-1184.
[8]邢君.钢筋混凝土底框砌体结构抗火性能校核方法[J].消防科学与技术,2016,35(3):301-304.
[9]廖艳芬,漆雅庆,马晓茜.钢筋混凝土框架抗火性能的有限元分析[J].消防科学与技术,2011,30(12):1100-1105.
[2]DHANASEKAR M,KLEEMAN P W,PAGE A W.Biaxial stress-strain relations for brick masonry[J].Journal of Structural Engineering,1985,111(5):1085-1100.
[3]LIE T T,IRWIN R J.Fire resistance of rectangular steel columns filled with bar-reinforced concrete[J].Journal of Structural Engineering,1994,120(5):1489-1509.
[4]高皖杨,胡克旭.碳纤维加固混凝土梁耐火试验研究与理论分析[D].上海:同济大学,2007.
[5]杨卫忠.砌体受压本构关系模型[J].建筑结构,2008,(10):80-82.
[6]姚亚雄,朱伯龙.钢筋混凝土框架结构抗火试验研究[J].同济大学学报,1996,(6):619-624.
[7]张耕源,邱仓虎,白连平,等.某车辆段现浇整体式梁板耐火性能研究[J].消防科学与技术,2018,37(9):1181-1184.
[8]邢君.钢筋混凝土底框砌体结构抗火性能校核方法[J].消防科学与技术,2016,35(3):301-304.
[9]廖艳芬,漆雅庆,马晓茜.钢筋混凝土框架抗火性能的有限元分析[J].消防科学与技术,2011,30(12):1100-1105.