Effect analysis of steel-concrete composite beam caused by sudden change of temperature
-
摘要: 对自然环境内钢-混凝土组合梁截面内温度进行了测试, 以温差梯度为计算模型, 基于弹性理论, 推导了不同温差模式下组合梁交界面上的剪力、剪应力、相对滑移应变与变形以及弯曲变形曲率计算公式。分析结果表明: 在自然温变情况下组合梁截面内存在温差, 同时混凝土翼板内温度分布不均匀; 界面剪力最大值在跨中部位, 向梁端部逐渐递减为0;剪应力、相对滑移应变与变形在梁端部达到最大值, 向跨中逐渐递减为0;界面内力及变形与温差大小呈线性正比, 斜率与混凝土板内温度分布模式有关; 混凝土板内温度分布模式及厚度是截面内力和变形的主要影响因素。Abstract: The temperatures of steel-concrete composite beam cross-sections under nature condition were tested, the formulae of steel-concrete composite beam interfacial shear force, shear stress, relative slide strain and deformation, flexural deformation curvature were derived by using temperature gradient calculation model and elastic theory. Analysis result shows that there is temperature difference in the cross-section, and the temperature distribution of concrete flange slab is uneven. The maximum interfacial shear force is at the midspan and decreases to zero at the end of beam. The maximum interfacial shear stress, relative slide strain and deformation are at the end of beam and decrease to zero at the midspan. Interfacial force and deformation are linearly proportional to temperature difference, and the slope is associated with the temperature distribution modes of concrete slab. The temperature distribution mode and thickness of concrete slab are the main influence factors of interfacial force and deformation.
-
表 1 不同温差梯度计算结果
Table 1. Calculation results of different temperature gradients
温差梯度 最大值 温度模式a 温度模式b 有限元法 实测值[17] T(y)=15 ℃t1=15 ℃t2=6.7 ℃ T(x)/kN 2 035 2 149 1 974 τ(x)/MPa 9.41 9.94 8.74 S(x)/mm 0.74 0.78 0.76 0.77 T(y)=20 ℃t1=20 ℃t2=6.7 ℃ T(x)/kN 2 393 2 866 2 332 τ(x)/MPa 11.07 13.25 9.96 S(x)/mm 0.87 1.04 0.81 0.98 T(y)=25 ℃t1=25 ℃t2=6.7℃ T(x)/kN 2 751 3 582 2 696 τ(x)/MPa 12.72 16.57 11.54 S(x)/mm 1.00 1.31 0.99 1.25 T(y)=30 ℃t1=30 ℃t2=6.7 ℃ T(x)/kN 3 109 4 299 3 061 τ(x)/MPa 14.38 19.88 12.94 S(x)/mm 1.13 1.57 1.21 1.43 -
[1] 余志武, 丁发兴. 钢-混凝土组合结构抗火性能研究与应用[J]. 建筑结构学报, 2010, 31(6): 96-109. https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201006012.htmYU Zhi-wu, DING Fa-xing. Fire performance research and application on steel-concrete composite structures[J]. Journal of Building Structures, 2010, 31(6): 96-109. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201006012.htm [2] 宋天诣, 韩林海. 组合结构耐火性能研究的部分新进展[J]. 工程力学, 2008, 25(增Ⅱ): 230-253. https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX2008S2027.htmSONG Tian-yi, HAN Lin-hai. Some new developments of the fire performance research on composite structures[J]. Engineering Mechanics, 2008, 25(SⅡ): 230-253. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX2008S2027.htm [3] 林错错, 王元清, 石永久. 露天日照条件下钢结构构件的温度场分析[J]. 钢结构, 2010, 25(8): 38-43, 31. doi: 10.3969/j.issn.1007-9963.2010.08.009LIN Cuo-cuo, WANG Yuan-qing, SHI Yong-jiu. Analysis of the temperature field of steel members in sunshine[J]. Steel Construction, 2010, 25(8): 38-43, 31. (in Chinese). doi: 10.3969/j.issn.1007-9963.2010.08.009 [4] GARLOCK M E, SELAMET S. Modeling and behavior of steel plate connections subject to various fire scenarios[J]. Journal of Structural Engineering, 2010, 136(7): 897-906. doi: 10.1061/(ASCE)ST.1943-541X.0000179 [5] RANZI G, BRADFORD M A. Analytical solutions for elevated-temperature behavior of composite beams with partial interaction[J]. Journal of Structural Engineering, 2007, 133(6): 788-799. doi: 10.1061/(ASCE)0733-9445(2007)133:6(788) [6] 李国强, 周宏宇. 钢-混凝土组合梁抗火性能试验研究[J]. 土木工程学报, 2007, 40(10): 19-26. doi: 10.3321/j.issn:1000-131x.2007.10.004LI Guo-qiang, ZHOU Hong-yu. Experimental study on the fire-resistance of steel-concrete composite beams[J]. China Civil Engineering Journal, 2007, 40(10): 19-26. (in Chinese). doi: 10.3321/j.issn:1000-131x.2007.10.004 [7] 李国强, 王卫永, 周宏宇. 简支组合梁抗火设计简化方法[J]. 建筑结构, 2010, 40(6): 35-38. https://www.cnki.com.cn/Article/CJFDTOTAL-JCJG201006013.htmLI Guo-qiang, WANG Wei-yong, ZHOU Hong-yu. Simplified approach for fire-resistance design of simple-supportedcomposite beams[J]. Building Structure, 2010, 40(6): 35-38. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JCJG201006013.htm [8] 吕俊利, 董毓利, 杨志年. 受火条件下整体结构中组合梁破坏形态研究[J]. 沈阳建筑大学学报: 自然科学版, 2010, 26(5): 823-827. https://www.cnki.com.cn/Article/CJFDTOTAL-SYJZ201005005.htmLU Jun-li, DONG Yu-li, YANG Zhi-nian. Study of the composite beams failure modes in whole structure under fire[J]. Journal of Shenyang Jianzhu University: Natural Science, 2010, 26(5): 823-827. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-SYJZ201005005.htm [9] 毛小勇, 肖岩. 标准升温下轻钢-混凝土组合梁的抗火性能研究[J]. 湖南大学学报: 自然科学版, 2005, 32(2): 64-70. doi: 10.3321/j.issn:1000-2472.2005.02.015MAO Xiao-yong, XIAO Yan. Behavior of lightweight steelconcrete composite beams subjected to standard fire[J]. Journal of Hunan University: Natural Sciences, 2005, 32(2): 64-70. (in Chinese). doi: 10.3321/j.issn:1000-2472.2005.02.015 [10] NIE Jian-guo, TAO Mu-xuan, CAI C S, et al. Analytical and numerical modeling of prestressed continuous steelconcrete composite beams[J]. Journal of Structural Engineering, 2011, 137(12): 1405-1418. doi: 10.1061/(ASCE)ST.1943-541X.0000409 [11] FORABOSCHI P. Analytical solution of two-layer beam taking into account nonlinear interlayer slip[J]. Journal of Engineering Mechanics, 2009, 135(10): 1129-1146. doi: 10.1061/(ASCE)EM.1943-7889.0000043 [12] NIE Jian-guo, TAO Mu-xuan, CAI C S, et al. Deformation analysis of prestressed continuous steel-concrete composite beams[J]. Journal of Structural Engineering, 2009, 135(11): 1377-1389. doi: 10.1061/(ASCE)ST.1943-541X.0000067 [13] GATTESCO N, MACORINI L, FRAGIACOMO M. Moment redistribution in continuous steel-concrete composite beams with compact cross section[J]. Journal of Structural Engineering, 2010, 136(2): 193-202. [14] NIE Jian-guo, TANG Liang, CAI C S. Performance of steelconcrete composite beams under combined bending and torsion[J]. Journal of Structural Engineering, 2009, 135(9): 1048-1057. [15] MARTINELLI E, FAELLA C, DI PALMA G. Shear-flexible steel-concrete composite beams in partial interaction: closed-form"exact"expression of the stiffness matrix[J]. Journal of Engineering Mechanics, 2012, 138(2): 151-163. doi: 10.1061/(ASCE)EM.1943-7889.0000320 [16] 蒋丽忠, 余志武, 李佳. 均布荷载作用下钢-混凝土组合梁滑移及变形的理论计算[J]. 工程力学, 2003, 20(2): 133-137. https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX200302024.htmJIANG Li-zhong, YU Zhi-wu, LI Jia. The oretical analysis of slip and deformation of steel-concrete composite beam under uniformly distributed loads[J]. Engineering Mechanics, 2003, 20(2): 133-137. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX200302024.htm [17] 吴迅, 陈经伟, 肖春, 等. 温差、收缩引起的钢-混凝土组合梁界面处剪力作用研究[J]. 结构工程师, 2009, 25(1): 41-44, 54. https://www.cnki.com.cn/Article/CJFDTOTAL-JGGC200901010.htmWU Xun, CHEN Jing-wei, XIAO Chun, et al. Study on shear effect caused by temperature and shrinkage on the interface of steel-concrete composite beams[J]. Structural Engineers, 2009, 25(1): 41-44, 54. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JGGC200901010.htm