Experimental and numerical investigation of steel-timber composite beams under concentrated load
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摘要:
目的 用钢材替代工字型木梁的腹板部分以解决纯木梁腹板易剪切破坏、抗弯刚度低的问题，有助于减小构件尺寸，增加其在大跨度建筑中的应用。 方法 在H型钢上下翼缘各覆一层木材并使用螺栓连接制备组合梁。对11根组合梁开展三点弯曲试验，研究螺栓间距、剪跨比对组合梁破坏模式、刚度和承载力的影响。通过4个推出试验研究钢木界面滑移对组合梁性能的影响。 结果 钢木组合梁的抗弯刚度比相同截面尺寸的矩形木梁提高了201%；H型钢在集中荷载作用下易发生上翼缘的局部屈曲，剪跨比为2时，试件出现脆性破坏特征，破坏始于上层木材，随着剪跨比增大，试件由脆性破坏转变为延性破坏，木材最先破坏位置由上层木材转变为下层木材；剪跨比增大时，组合梁抗弯刚度减小，延性系数增大，峰值荷载下降了15%以上；螺栓间距增大时，组合梁抗弯刚度增大，延性系数减小，峰值荷载上升了15%以上。考虑钢木界面滑移的屈服承载力和跨中挠度的计算公式具有较高的准确性，所得计算值与试验值误差基本在10%以内；由材性试验获取材性参数，在此基础上使用ABAQUS软件建立考虑钢木界面滑移的有限元模型，模拟结果较为准确，组合梁抗弯刚度和屈服荷载的模拟值与试验值误差基本在10%以内。 结论 钢材用作腹板部分可以显著提高梁的抗弯刚度，并防止腹板剪切破坏；考虑界面滑移后，组合梁抗弯性能的理论计算和有限元模拟结果均较为准确。 Abstract:Objective Replacing the web of I-shaped timber beam with steel can solve the problems of web shear failure and low bending stiffness of bare timber beam. This helps to reduce the component size and increase its application in large-span buildings. Method The steel-timber composite (STC) beam was prepared by connecting two timber slabs on the H-shaped steel flanges with bolts. The influence of different bolt spacing and shear-span ratio on the structural behavior (failure modes, stiffness and load capacity) of STC beams were studied. Three-point bending tests were carried out on 11 STC beams. Four push-out tests were carried out to investigate steel-timber interface slip. Result The bending stiffness of the STC beams was 201% higher than that of the rectangular timber beam with the same section size. The steel upper flange was prone to buckle by concentrate load. Increasing the shear-span ratio, the failure converts from brittle to ductile, the initial failure transforms from top timber slab to bottom. Increasing the shear-span ratio or decreasing the bolt spacing, the bending stiffness was declined, the ductility coefficient was improved and the peak load decreased by more than 15%. The formulations of yield load and mid-span deflection considering interface slip between steel and timber were proposed, the error of most specimens was less than 10% between calculated and experimental results. In addition, referencing material properties and push-out test, the finite element models of STC beams were established. The errors between simulated and experimental values of bending stiffness and yield load were basically within 10%. Conclusion Steel used as the web can significantly improve the bending stiffness of beams and prevent shear failure of webs. Considering the interface slip, the theoretical calculation and simulation results of flexural performance of STC beams are accurate. -
图 6 荷载–界面滑移曲线
200-1和300-1分别表示螺栓间距为200和300 mm的第1个推出试件；200-2和300-2分别表示螺栓间距为200和300 mm的第2个推出试件。200-1 and 300-1 represent the first push-out specimens with bolt spacing of 200 and 300 mm, respectively. 200-2 and 300-2 represent the second push-out specimens with bolt spacing of 200 and 300 mm, respectively.
Figure 6. Load versus interface slip curves
图 10 组合梁的横截面和应力分布
b1、b2、b3为第一、二、三部分界面宽度(mm)；h1、h2、h3为第一、二、三部分截面高度(mm)；A1、A2、A3为第一、二、三部分截面面积(mm2)；I1、I2、I3为第一、二、三部分惯性矩(mm4)；E1、E2、E3为第一、二、三部分弹性模量(MPa)；a1、a2、a3为第一、二、三部分中性轴到组合梁中性轴的距离(mm)；σ1、σ2、σ3为第一、二、三部分中性轴对应应力(MPa)；σm,1、σm,2、σm,3为第一、二、三部分最大应力与中性轴应力的差值(MPa)。 b1, b2, b3 are section width of the first, second, third part (mm). h1, h2, h3 are the section height of the first, second, third part (mm). A1, A2, A3 are the cross-sectional area of the first, second, third part (mm2). I1, I2, I3 are inertial moment of the first, second, third part (mm4). E1, E2, E3 are elastic modulus of the first, second, third part (MPa). a1, a2, a3 are the distance from the neutral axis of the first, second, third part to the neutral axis of the composite beam(mm). σ1, σ2, σ3 are the corresponding stress of neutral axis of the first, second, third part (MPa). σm,1, σm,2, σm,3 are the difference between the maximum stress of the first, second, third part and the neutral axis stress (MPa).
Figure 10. Cross section and bending stress distribution of composite beams
图 11 试件有限元网格划分及边界条件
Figure 11. Mesh and boundary conditions of the finite element model
图 13 有限元模拟和试验的荷载–跨中挠度曲线对比
Figure 13. Comparison of simulated and experimental load versus mid-span deflection curves
表 1 试件参数
Table 1. Parameters of specimens
各组编号
Specimen No.螺栓间距
Bolt spacing/mm螺栓端距
Bolt end distance/mm长度
Length/mm跨度
Span/mm剪跨比
Shear-span ratio数量
NumberS2-200 200 50 900 704 2 2 S3-200 200 50 1 300 1 056 3 2 S4-200 200 100 1 600 1 408 4 2 S2-300 300 150 900 704 2 2 S3-300 300 50 1 300 1 056 3 2 S4-300 300 50 1 600 1 408 4 1 注：试件编号中S代表剪跨比，其值为2、3、4，200和300为螺栓间距。Notes：S represents the shear-span ratio in the specimen No., with values of 2, 3 and 4, and 200 and 300 are the bolt spacing. 
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表 2 屈服荷载的计算值与试验值比较
Table 2. Comparison between calculated and experimental yield load
剪跨比
Shear-span ratio螺栓间距
Bolt spacing/mm滑移刚度
Slip stiffness/
(kN·mm−1)有效抗弯刚度
Effective bending
stiffness/(kN·m2)屈服荷载计算值
Calculated yield load/kN屈服荷载试验值
Experimental yield
load/kN误差
Error/%2 200 6.58 768.92 113.6 125.3 −9.32 3 200 6.58 796.84 78.5 86.6 −9.39 4 200 6.58 824.45 60.9 65.4 −6.91 2 300 9.14 767.02 113.3 120.7 −6.11 3 300 9.14 792.87 78.1 98.2 −20.44 4 300 9.14 818.44 60.5 72.8 −16.91
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表 3 挠度的计算值与试验值的比较
Table 3. Comparison of calculated and experimental deflection
剪跨比
Shear-span ratio荷载
Load/kN挠度计算值
Calculated deflection/mm挠度试验值
Experimental deflection/mm误差
Error/%2 40 1.190 1.167 1.97 3 40 2.137 2.213 −3.45 4 40 3.824 4.259 −10.20
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表 4 木材和钢材的材性参数
Table 4. Mechanical properties of timber and steel
材料
Material弹性模量 Elastic modulus/MPa 剪切模量 Shear modulus/MPa 泊松比 Poisson’s ratio EL ER ET GLR GLT GRT μLR μLT μRT 二等云杉 Second grade spruce 5 600 436.8 240.8 358.4 341.6 16.8 0.372 0.467 0.435 钢材 Steel 2.0 × 105 76923 0.3 注：EL、ER、ET分别表示顺纹、径向和弦向的弹性模量; GLR、GLT、GRT表示径向、弦向和横纹3个方向的剪切弹性模量; μLR、μLT、μRT表示纵径向、纵弦向、径弦向3个方向的泊松比。Notes: EL, ER, ET represent elastic modulus along grain, radial and tangential direction, respectively. GLR, GLT, GRT represent shear elastic modulus along radial, tangential and perpendicular grain direction, respectively. μLR, μLT, μRT represent Poisson’s ratio along parallel grain versus radial, parallel grain versus tangential and radial versus tangential direction, respectively.
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表 5 屈服荷载和刚度的有限元模拟值与试验值对比
Table 5. Comparison of finite element simulated and experimental yield load and stiffness
剪跨比
Shear-span ratio屈服荷载 Yield load 刚度 Stiffness 模拟值
Simulated value/kN试验值
Experimental value/kN误差
Error/%模拟值
Simulated value/
(kN·mm−1)试验值
Experimental value/
(kN·mm−1)误差
Error/%2 147.48 122.21 20.68 35.44 34.36 3.15 3 92.29 92.38 −0.10 18.14 18.16 −0.12 4 68.72 67.86 1.26 9.90 9.14 8.34
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[1] 谌晓梦. 建筑用木材的使用初探[J]. 中国建材科技, 2020, 29(1):105−107.Shen X M. Brief discussion on use of building timber[J]. China Building Materials Science & Technology, 2020, 29(1): 105−107. [2] 简伟通, 沈冬儿. 建筑工业化背景下我国木结构的发展趋势[J]. 重庆建筑, 2018, 17(8):10−11. doi: 10.3969/j.issn.1671-9107.2018.08.10Jian W T, Shen D E. Development trend of wood structure in China under the background of architectural industrialization[J]. Chongqing Architecture, 2018, 17(8): 10−11. doi: 10.3969/j.issn.1671-9107.2018.08.10 [3] 吴树栋. 木材在建筑节能和优化社会材料结构中的作用[J]. 木材工业, 2008(3):1−4.Wu S D. Role of wood products in energy saving for buildings[J]. China Wood Industry, 2008(3): 1−4. [4] 龚迎春, 娄万里, 李明月, 等. 我国木结构产业发展展望[J]. 木材工业, 2019, 33(5):20−24.Gong Y C, Lou W L, Li M Y, et al. Prospects for timber structure industry in China[J]. China Wood Industry, 2019, 33(5): 20−24. [5] 张如玉, 杨宝磊, 李国东, 等. 钢木组合结构研究综述[J]. 山西建筑, 2019, 45(11):52−53. doi: 10.3969/j.issn.1009-6825.2019.11.027Zhang R Y, Yang B L, Li G D, et al. Research review of steel-wood composite structure[J]. Shanxi Architecture, 2019, 45(11): 52−53. doi: 10.3969/j.issn.1009-6825.2019.11.027 [6] 白润山, 江卓林. 浅谈钢木组合结构研究进展[J]. 河北建筑工程学院学报, 2016, 34(3):75−78. doi: 10.3969/j.issn.1008-4185.2016.03.016Bai R S, Jiang Z L. Research on steel-wood composite structure[J]. Journal of Hebei Institute of Architecture and Civil Engineering, 2016, 34(3): 75−78. doi: 10.3969/j.issn.1008-4185.2016.03.016 [7] de Angelis A, Pecce M R, Logorano G. Evaluation of the plastic hinge length of steel-concrete composite beams under hogging moment[J]. Engineering Structures, 2019, 191(14): 674−685. [8] 李登辉. 钢–木组合梁抗弯性能研究[D]. 北京: 北京交通大学, 2016.Li D H. Study on flexural behavior of steel-wood composite beam[D]. Beijing: Beijing Jiaotong University, 2016. [9] 贺洁为. 热轧H型钢–落叶松木组合梁受弯性能研究[D]. 长沙: 中南林业科技大学, 2019.He J W. Research on the being bent composite beams of hot-rolled H steel and larch[D]. Changsha: Central South University of Forestry & Technology, 2019. [10] Hassanieh A, Valipour H R, Bradford M A. Experimental and numerical investigation of short-term behaviour of CLT-steel composite beams[J]. Engineering Structures, 2017, 144(15): 43−57. [11] 沈银澜, 牟在根, Stiemer S F, 等. 正交胶合木填充墙–钢框架体系受力性能[J]. 工程科学学报, 2017, 39(1):155−165.Shen Y L, Mou Z G, Stiemer S F, et al. Mechanical performance of cross laminated timber infill wall-steel frames[J]. Chinese Journal of Engineering, 2017, 39(1): 155−165. [12] Hu Q B, Gao Y, Meng X M, et al. Axial compression of steel-timber composite column consisting of H-shaped steel and glulam[J]. Engineering Structures, 2020, 216(15): 110561. [13] 李威, 高颖, 孟鑫淼, 等. 角钢–集成材L形组合柱的受压性能研究[J]. 林业工程学报, 2020, 5(1):53−60.Li W, Gao Y, Meng X M, et al. Study on compressive performance of angel steel-glued laminated timber L-shaped composite column[J]. Journal of Forestry Engineering, 2020, 5(1): 53−60. [14] 李国东, 陈文强. 冷弯薄壁型钢–胶合木组合梁受剪性能研究[J]. 低温建筑技术, 2020, 42(1):49−53.Li G D, Chen W Q. Research on shear properties of cold-formed steel-glued wood composite beams[J]. Low Temperature Architecture Technology, 2020, 42(1): 49−53. [15] 陈爱国, 李登辉, 方超, 等. H形钢–木组合梁受弯性能试验研究[J]. 建筑结构学报, 2016, 37(增刊 1):261−267.Chen A G, Li D H, Fang C, et al. Experimental study on flexural behavior of H-shaped steel-wood composite beams[J]. Journal of Building Structures, 2016, 37(Suppl. 1): 261−267. [16] Hassanieh A, Valipour H R, Bradford M A. Load-slip behaviour of steel-cross laminated timber (CLT) composite connections[J]. Journal of Constructional Steel Research, 2016, 122(7): 110−121. [17] 方超. 钢–木组合连接静力性能研究[D]. 北京: 北京交通大学, 2015.Fang C. Analysis of static performance in steel-wood connection[D]. Beijing: Beijing Jiaotong University, 2015. [18] 文林峰. 装配式木结构技术体系和工程案例汇编[M]. 北京: 中国建筑工业出版社, 2019.Wen L F. Technical system and compilation of engineering cases of assembly wood structure[M]. Beijing: China Architecture & Building Press, 2019. [19] 金许奇, 柏亚双, 徐国林. 基于螺栓连接的薄壁钢–木组合梁承载力影响因素分析[J]. 西南林业大学学报(自然科学), 2018, 38(4):167−172.Jin X Q, Bai Y S, Xu G L. Analysis of influencing factors on bearing capacity of thin-walled steel-wood composite beams connected by bolts[J]. Journal of Southwest Forestry University (Natural Sciences), 2018, 38(4): 167−172. [20] Hassanieh A, Valipour H R, Bradford M A. Experimental and numerical study of steel-timber composite (STC) beams[J]. Journal of Constructional Steel Research, 2016, 122(7): 367−378. [21] 冯鹏, 强翰霖, 叶列平. 材料、构件、结构的“屈服点”定义与讨论[J]. 工程力学, 2017, 34(3):36−46. doi: 10.6052/j.issn.1000-4750.2016.03.0192Feng P, Qiang H L, Ye L P. Discussion and definition on yield points of materials, members and structures[J]. Engineering Mechanics, 2017, 34(3): 36−46. doi: 10.6052/j.issn.1000-4750.2016.03.0192 [22] 赵卫锋, 曹勇龙, 周靖, 等. 薄壁方钢管/竹胶合板组合空芯柱偏心抗压试验研究[J]. 建筑材料学报, 2015, 18(4):601−607. doi: 10.3969/j.issn.1007-9629.2015.04.012Zhao W F, Cao Y L, Zhou J, et al. Eccentric compression experimental study on square thin-walled steel tube/bamboo-plywood composite hollow column[J]. Journal of Building Materials, 2015, 18(4): 601−607. doi: 10.3969/j.issn.1007-9629.2015.04.012 [23] 朱忠漫. 干缩裂缝对历史建筑木构件受力性能影响的试验研究[D]. 南京: 东南大学, 2015.Zhu Z M. Experimental research on mechanical properties of timber structural members with shrinkage cracks in historic buildings[D]. Nanjing: Southeast University, 2015. -
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