地震作用下钢筋混凝土悬臂梁抗弯性能及尺寸效应试验研究

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振动与冲击 ›› 2017, Vol. 36 ›› Issue (13) : 19-26.

论文

金浏，苏晓，李冬，杜修力

作者信息 +

Experimental study on flexural behavior and size effect of RC cantilever beams subjected to seismic loading

Liu JIN, Xiao SU, Dong LI, Xiuli DU

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文章历史 +

摘要

随着建筑结构尺寸的不断增大，准确的预测地震荷载作用下钢筋混凝土梁抗震性能及抗弯强度随构件尺寸增大的变化趋势对评估结构的安全性具有重要的意义。本文设计了剪跨比为4的五组几何相似的钢筋混凝土悬臂梁，对其在低周往复荷载作用下的抗弯性能进行试验研究，旨在探讨悬臂梁的破坏模式、延性、耗能能力，刚度退化及抗弯强度等与构件尺寸的关系。研究表明：1)不同尺寸梁的破坏模式基本相同，均在梁的固定端发生累积压缩破坏；2)随着梁尺寸增加，其延性有所增强，但耗能能力及刚度退化性能基本相同；3)低周往复荷载作用下梁的名义抗弯强度存在明显的尺寸效应；4)Bažant尺寸效应理论能较好的描述钢筋混凝土悬臂梁在低周往复荷载作用下的尺寸效应规律。

Abstract

As the structural dimension increases, precise prediction for the hysteresis behavior and the nominal bending strength of reinforced concrete (RC) cantilever beams having different structural sizes under seismic loads is of great importance on assessing the safety of RC frames. In the present study, five groups of geometrically similar RC cantilever beams with a shear span ratio of 4 was designed and tested under low cyclic loading. The mechanical behavior including the failure pattern, ductility, energy dissipation capacity, stiffness degradation behavior and bending bearing capacity was examined and discussed. The test observations indicate that, 1) the failure patterns of all the tested RC beams with different structural sizes were similar, and all the beams failed at the end of the specimens due to concrete crushing; 2)with the increase of beam size, the ductility of specimen increases, while the energy dissipation capacity and stiffness degradation do not change; 3) the nominal flexural strength of the RC beams under low cyclic loading presents a strong size effect; and 4) the size effect of RC cantilever beams under cyclic loading follows closely the size effect law proposed by Bažant.

导出引用

金浏，苏晓，李冬，杜修力. 地震作用下钢筋混凝土悬臂梁抗弯性能及尺寸效应试验研究[J]. 振动与冲击, 2017, 36(13): 19-26

Liu JIN, Xiao SU, Dong LI, Xiuli DU. Experimental study on flexural behavior and size effect of RC cantilever beams subjected to seismic loading[J]. Journal of Vibration and Shock, 2017, 36(13): 19-26

参考文献

[1] Bažant Z P, Planas J. Fracture and size effect in concrete and other quasi-brittle materials [M]. CRC press, 1997, 7-15.
[2] Hoover C G, Bažant Z P. Comprehensive concrete fracture tests: size effects of types 1 & 2, crack length effect and postpeak [J]. Engineering Fracture Mechanics, 2013, 110: 281-289.
[3] 王立成, 邢立坤, 宋玉普. 混凝土劈裂抗拉强度和弯曲抗压强度尺寸效应的细观数值分析[J]. 工程力学, 2014, 31(10): 69-76. WANG Licheng, XING Likun, SONG Yupu. Mesoscale modeling on size effect of splitting tensile strength and flexural compressive strength of concrete [J]. Engineering Mechanics, 2014, 31(10): 69-76.
[4] 苏捷, 方志, 杨钻. 骨料组分和强度等级对混凝土单轴受压性能尺寸效应的影响[J]. 建筑结构学报, 2014, 35(5): 120-127. (Su Jie, Fang Zhi, Yang Zuan. Influence of aggregate mixture and strength grade on dimensional effect of concrete uniaxial compressive behavior [J]. Journal of Building Structures, 2014, 35(5): 120-127.)
[5] Li Dong, Jin Liu, Du Xiuli, Fu Jia. Size effect tests of normal-strength and high-strength RC columns subjected to axial compressive loading [J]. Engineering Structures, 2016, 109: 43-60.
[6] 李冬, 金浏, 杜修力. 钢筋混凝土柱轴心受压性能及尺寸效应的细观数值研究[J]. 水利学报, 2016, 47(1): 209-218. (Li Dong, Jin Liu, Du Xiuli. Mesoscopic simulation of the mechanical properties and the size effect of reinforced concrete column subjected to axial compressive loading [J]. Journal of Hydraulic Engineering, 2016, 47(1): 209-218.)
[7] Bažant Z P, Kwon Y W. Failure of slender and stocky reinforced concrete columns: tests of size effect [J]. Materials and Structures, 1994, 27(2):79-90.
[8] Şener S, Barr B I G, Abusiaf H F. Size effect in axially loaded reinforced concrete columns [J]. ASCE Journal of Structural Engineering, 2004, 130(4): 662-670.
[9] Bažant Z P, Kim J-K. Size effect in shear failure of longitudinally reinforced beams [J]. ACI Journal Proceedings, 1984, 81(5): 456-468.
[10] Zararis P D, Papadakis G C. Diagonal shear failure and size effect in RC beams without web reinforcement [J]. Journal of Structural Engineering, 2001, 127(7): 733-742.
[11] Syroka-Korol E, Tejchman J. Experimental investigations of size effect in reinforced concrete beams failing by shear [J]. Engineering Structures, 2014, 58: 63-78.
[12] Barbhuiya S, Choudhury A M. A study on the size effect of RC beam-column connections under cyclic loading [J]. Engineering Structures, 2015, 95:1-7.
[13] Yu Q, Bažant ZP. Can stirrups suppress size effect on shear strength of RC beams [J]? ASCE Journal Structural Engineering, 2011, 137(5): 607-17.
[14] Ožbolt J, Meštrovic D, Li Y J, Eligehausen R. Compression failure of beams made of different concrete types and sizes [J]. ASCE Journal of Structural Engineering, 2000, 126(2): 200-209.9.
[15] 车轶, 郑新丰, 王金金, 宋玉普. 单调荷载作用下高强混凝土梁受弯性能尺寸效应研究[J]. 建筑结构学报, 2012, 33(6): 96-102. CHE Yi, ZHENG Xinfeng, WANG Jinjin. Size effect on flexural behavior of reinforced high-strength concrete beams subjected to monotonic loading [J]. Journal of Building Structures, 2012, 33(6): 96-102.
[16] 车轶, 王金金, 郑新丰,宋玉普. 反复荷载作用下高强混凝土梁受弯性能尺寸效应试验研究[J]. 建筑结构学报, 2013, 34(8): 100-106. CHE Yi, ZHENG Xinfeng, WANG Jinjin, SONG Yupu. Experimental study on size effect of flexural behavior of reinforced high-strength concrete beams subjected to cyclic loading [J]. Journal of Building Structures, 2012, 33(6): 96-102.
[17] Weiss W J, Gular K, Shah S P, Localization and size-dependent response of reinforced concrete beams [J]. ACI Structural Journal, 2001, 98 (5): 686-695.
[18] Carpinteri A, Corrado M, Paggi M, Mancini G. New model for the analysis of size-scale effects on the ductility of reinforced concrete elements in bending [J]. ASCE Journal of Engineering Mechanics, 2009, 135(3): 221-229.
[19] Rao G A, Vijayanand I, Eligehausen R. Studies on ductility and evaluation of minimum flexural reinforce- ment in RC beams [J]. Materials and Structures, 2008, 41 (4): 759-71.
[20] Bažant Z P. Size effect in blunt fracture: concrete, rock, metal [J]. ASCE Journal of Engineering Mechanics, 1984, 110(4): 518-535.