-
摘要: 为研究高强钢-混凝土组合梁中结构几何参数及材料强度对组合梁受力性能的影响, 建立了14组构件在跨中两点对称荷载作用下的有限元数值模型, 对其受力性能进行了分析。分析结果表明: 在承载能力极限状态下, 钢梁的贡献占竖向抗剪强度约77.0%;在弹性与塑性阶段, 不同材料强度的组合梁的跨中最小与最大挠度比值分别为79.5%和28.0%;在塑性状态下, 不同混凝土板横向配筋率和宽度的组合梁的跨中最小与最大挠度比值分别为62.1%和53.3%, 不同材料强度、混凝土板宽度、横向配筋率和厚度的组合梁的最小与最大纵向滑移量比值分别为25.0%、41.9%、63.2%、70.7%。可见, 提高钢梁强度或增大钢梁尺寸可显著提高组合梁竖向抗剪能力; 材料强度对组合梁弹性工作阶段的跨中挠度影响较小, 混凝土板横向配筋率及其宽度对塑性状态下跨中挠度有较大影响; 弹性工作阶段材料与几何参数对组合面滑移的影响不明显, 塑性状态下材料强度、混凝土板宽度、横向配筋率及厚度对纵向滑移影响较大。Abstract: In order to study structural behaviors of high strength steel-concrete composite girders, 14 group-components models with different geometry parameters and material properties were built by using ANSYS software under deuce symmetrical loads at mid-span.The analysis result indicates that steel girder bears about 77.0% of whole vertical shear strength in plastic state, and the ratios of maximum and minimum values of mid-span deflections for different material strength girders in elastic and plastic states are 79.5% and 28.0% respectively; the ratios of maximum and minimum values of mid-span deflections for different transverse bar ratios and widthes of concrete slab girders in plastic state are 62.1% and 53.3% respectively; the ratios of maximum and minimum values of longitudinal slips for different material strengthes, widthes of concrete slab, transverse bar ratios and thicknesses of concrete deck girders in plastic state are 25.0%, 41.9%, 63.2% and 70.7% respectively.Therefore, increasing the strength and section size of steel is economic and reasonable method to increase the vertical shear strength of the girders; the steel and concrete strengthes affect little on the mid-span deflection of the girders in elastic state, and the transverse bar ratio and the width of concrete slab have larger effect on the mid-span deflection in plastic state; the geometry parameters and material properties of the girders have little effect on the longitudinal slip in elastic state, but the material strength, width of concrete slab, transverse bar ratio and thickness of concrete deck have obvious effects on the longitudinal slip in plastic state.
-
表 1 材料及主要参数
Table 1. Materials and main parameters
表 2 混凝土材料性质
Table 2. Material properties of concretes
强度等级 fcu, 15 fcu, 10 fc εc0 εcu Ec υ ft ρc C60 60 64.8 53.7 0.002 1 0.003 0 35 902 0.25 3.388 2 600 C70 70 75.8 63.0 0.002 2 0.003 0 38 009 0.25 3.761 2 600 C80 80 86.8 72.3 0.002 3 0.003 0 39 924 0.25 4.117 2 600 C40 40 — 26.8 0.001 8 0.003 3 32 500 0.20 2.390 2 600 C50 50 — 32.4 0.001 9 0.003 3 34 500 0.20 2.640 2 600 注: fcu, 15为边长为150 mm的混凝土立方体抗压强度, MPa; εcu为混凝土极限应变; υ为横向变形系数; ft为抗拉强度, MPa; ρc为密度, kg·m-3; C40、C50材料性质根据《混凝土结构设计规范》(GB 50010—2002)得到。 表 3 钢材性质
Table 3. Material properties of steels
钢材 fy Es Et ρs Q235 235 210 000 21 000 7 851 Q345 345 210 000 21 000 7 851 Q390 390 210 000 21 000 7 851 Q420 420 210 000 21 000 7 851 注: Et为屈服后硬化斜率, MPa; ρs为密度, kg·m-3; fy为屈服强度, MPa; Es为弹性模量, MPa。 表 4 各梁的特征外荷载、相应挠度及钢梁承受剪力
Table 4. Topical loads, deflections and shear forces of steel girders
-
[1] 徐岳, 朱万勇, 杨岳. 波形钢腹板PC组合箱梁桥抗弯承载力计算[J]. 长安大学学报: 自然科学版, 2005, 25(2): 60-64.Xu Yue, Zhu Wan-yong, Yang Yue. Calculation of ultimate moment capacity of prestressed concrete box-girder bridge with corrugated steel webs[J]. Journal of Chang'an University: Natural Science Edition, 2005, 25(2): 60-64. (in Chinese) [2] 黄侨, 郑一峰, 李光俊. 预弯组合梁非线性全过程分析方法[J]. 中国公路学报, 2006, 19(4): 88-93.Huang Qiao, Zheng Yi-feng, Li Guang-jun. Nonlinear whole course analysis method of preflex composite beam[J]. China Journal of Highway and Transport, 2006, 19(4): 88-93. (in Chinese) [3] 丁发兴, 余志武. 圆钢管自密实混凝土纯弯力学性能[J]. 交通运输工程学报, 2006, 6(1): 63-69.Ding Fa-xing, Yu Zhi-wu. Pure bending properties of self-compacting concrete filled circular steel tube[J]. Journal of Traffic and Transportation Engineering, 2006, 6(1): 63-69. (in Chinese) [4] AISC-LRFD—1994, Load and resistance factor design specification for structural steel buildings[S]. [5] Eurocode 4. Design of composite steel and concrete structures[S]. [6] GB50017—2003, 钢结构设计规范[S]. [7] 聂建国. 钢-混凝土组合梁结构: 试验、理论与应用[M]. 北京: 科学出版社, 2005. [8] 李惠. 高强度混凝土及其组合结构[M]. 北京: 科学出版社, 2004. [9] Jorgen G O, Roger GS, Fisher J W. Shear strength and steel connectors in lightweight and normal weight concrete[J]. AISC Engineering Journal, 1971, 8(2): 55-64. [10] 聂建国, 陈林, 肖岩. 钢-混凝土组合梁正弯矩区截面的组合抗剪性能[J]. 清华大学学报: 自然科学版, 2002, 42(6): 835-838.Nie Jian-guo, Chen Lin, Xiao Yan. Composite shear behavior of steel-concrete composite beams under sagging moment[J]. Journal of Tsinghua University: Science and Technology, 2002, 42(6): 835-838. (in Chinese) [11] 郑一峰, 黄侨, 冷曦晨. 预弯组合梁桥的弹塑性极限承载能力研究[J]. 中国公路学报, 2005, 18(4): 54-58.Zheng Yi-feng, Huang Qiao, Leng Xi-chen. Research on elastic-plastic ultimate capacity of preflex beambridges[J]. China Journal of Highway and Transport, 2005, 18(4): 54-58. (in Chinese) [12] 郑碧玉, 王社, 张亚亭, 等. 组合梁的应力分析与实验[J]. 长安大学学报: 自然科学版, 2006, 26(5): 62-65.Zheng Bi-yu, Wang She, Zhang Ya-ting, et al. Stress analysis and experiment of laminated beams[J]. Journal of Chang'an University: Natural Science Edition, 2006, 26(5): 62-65. (in Chinese) [13] 张清华, 李乔, 唐亮. 桥塔钢-混凝土结合段剪力键破坏机理及极限承载力[J]. 中国公路学报, 2007, 20(1): 85-90.Zhang Qing-hua, Li Qiao, Tang Liang. Fracture mechanism and ultimate carrying capacity of shear connectors applied for steel-concrete joint segment of bridge pylon[J]. China Journal of Highway and Transport, 2007, 20(1): 85-90. (in Chinese) [14] 翟越, 赵均海, 计琳, 等. 钢管混凝土轴向受压短柱承载力的统一解[J]. 长安大学学报: 自然科学版, 2006, 26(3): 55-58.Zhai Yue, Zhao Jun-hai, Ji Lin, et al. Unified solutions on axial compressive strength of concrete filled steel tube[J]. Journal of Chang'an University: Natural Science Edition, 2006, 26(3): 55-58. (in Chinese)