Experimental study on axial compression performance of T-section concrete filled steel and FRP tubular composite columns
-
摘要: 内置复材约束的T形截面钢管混凝土组合柱(T-section concrete filled steel and GFRP tubular composite column,T-SCFC)包括外部钢管、夹层混凝土、玻璃纤维增强树脂复合材料(Glass fiber reinforced polymer,GFRP)管和核心混凝土。对14根不同截面形式的约束混凝土短柱和3组内置不同复材管壁厚的T形截面钢管混凝土组合柱进行轴压试验,对比分析了方钢管混凝土短柱(Square concrete filled steel tube,CFST)、复材管约束混凝土短柱(Concrete filled GFRP tube,CFFT)、内置复材约束方钢管混凝土短柱(Steel-concrete-GFRP-concrete tube,SCFC)和T-SCFC柱在轴压荷载作用下的力学性能。建立与试件同尺寸的有限元模型,并开展数值参数分析,研究不同钢管壁厚和核心混凝土强度对T-SCFC柱轴心受压性能的影响。结果表明:内置约束复材管可以明显提高方钢管混凝土短柱的受压性能,显著延缓SCFC短柱在轴压荷载作用下的钢材屈服和鼓曲;T-SCFC柱在达到峰值荷载前,荷载-轴向位移曲线呈双线性增长,复材断裂后试件保持较高的残余承载力呈延性破坏,可以将复材断裂作为该类组合柱的失效点,增加复材管壁厚可以明显提高试件承载力;有限元模型计算结果与试验吻合较好;增加钢管壁厚可明显提高试件的承载力,提高试件核心混凝土强度仅对试件的等效屈服荷载有一定提高作用,对试件峰值承载力的影响较小。Abstract: The T-section concrete filled steel and glass fiber reinforced polymer (GFRP) tubular composite column (T-SCFC) is composed of external steel tube, sandwich concrete, GFRP tube and core concrete. Axial compression tests were carried out on 14 confined concrete short columns with different cross-section forms and three groups of concrete-filled steel tubular T-section columns with different wall thicknesses of GFRP tube. The mechanical properties of square concrete filled steel tube (CFST), concrete filled FRP tube (CFFT), steel-concrete-FRP-concrete (SCFC) short columns and T-SCFC columns under axial compression were compared and analyzed. The finite element model with the same size as the specimen was established, and the numerical parameter analysis was carried out to study the influence of steel tube wall thickness and core concrete strength on the axial compression performance of T-SCFC columns. The results show that the built-in GFRP tube can significantly improve the compression performance of concrete filled square steel tubular short columns, and significantly delay the steel yield and buckling of SCFC short columns under axial compression load. Before the peak load, the load-axial displacement curve of T-SCFC column increases bilinearly, and the residual bearing capacity of the specimen maintains high after fracture of the GFRP. The fracture of GFRP can be used as the failure point of the composite column. Increasing the wall thickness of GFRP tube can significantly improve the bearing capacity of the specimen. The calculation results of the finite element model are in good agreement with the test. Increasing the wall thickness of the steel tube can significantly improve the bearing capacity of the specimen. Improving the strength of the core concrete of the specimen only has a certain effect on the equivalent yield load of the specimen, and has little effect on the peak bearing capacity of the specimen.
-
图 4 应变测点布置及编号
Figure 4. Layout and number of strain measuring points
T-SCFC-H/2 Sx (Sy) represents the transverse (longitudinal) strain of H/2 section steel tube of T-SCFC column, respectively; FRP tubes built in the T-SCFC were numbered with Roman numerals, taking the FRP tube I as an example, Ix(Iy) represents the transverse (longitudinal) strain of the H/2 section of the GFRP tube, and two transverse strain measuring points I1/2, I9/10 were added to the H/4 and 3H/4 sections of the GFRP tube, respectively.
表 1 不同截面形式混凝土组合柱试件基本参数
Table 1. Basic parameters of concrete composite column specimens with different section forms
Specimen tf/mm ts/mm H/mm CFST-A/B — 4.5 300 CFFT-1-A/B 1 — 300 CFFT-2-A/B 2 — 300 CFFT-3-A/B 3 — 300 SCFC-1-A/B 1 4.5 300 SCFC-2-A/B 2 4.5 300 SCFC-3-A/B 3 4.5 300 T-SCFC-1-A/B 1 4.5 900 T-SCFC-2-A/B 2 4.5 900 T-SCFC-3-A/B 3 4.5 900 Notes: CFST—Square concrete filled steel tube; CFFT—Concrete filled GFRP tube; SCFC—Steel-concrete-FRP-concrete; T-SCFC—T-section concrete filled steel and GFRP tubular composite column; The naming formats of CFST, CFFT, SCFC and T-SCFC specimens are “CFST-y”, “CFFT-x-y”, “SCFC-x-y” and “T-SCFC-x-y”, x, y represent tube wall thickness and parallel specimen number, respectively; tf—Wall thickness of GFRP tube; ts—Wall thickness of steel tube; H-Height of specimen. 表 2 钢材力学性能
Table 2. Mechanical properties of steel
Material ft/MPa fy /MPa E/105MPa Q235B 381.56 313.22 2.02 Notes: ft—Tensile strength; fy—Yield strength; E—Elastic modulus. 表 3 玻璃纤维增强树脂复合材料(GFRP)管力学性能
Table 3. Mechanical properties of glass fiber reinforced polymer (GFRP) tube
tf/mm Eh/GPa σh/MPa εh Ea/GPa σa/MPa 1 81.13 823.26 0.012 6.63 127.29 2 62.33 610.97 0.010 4.57 110.41 3 65.17 683.51 0.011 3.46 134.95 Notes: Eh—Hoop tensile modulus; σh—Hoop tensile strength; εh—Cyclic tensile ultimate strain; Ea—Axial compression modulus; σa—Axial compressive strength. 表 4 SCFC与CFST短柱轴压承载力对比
Table 4. Comparison of axial compressive bearing capacity between SCFC and CFST short columns
Specimen Ny/kN Nmax/kN $ \eta $y/% $ \eta $max/% CFST-A/B 673.60 800.38 — — SCFC-1-A/B 806.00 978.24 19.6 22.20 SCFC-2-A/B 885.32 1097.08 31.4 37.07 SCFC-3-A/B 991.67 1298.56 47.2 62.20 Notes: Ny—Equivalent yield load; Nmax—Peak load; $ \eta $y—Increase ratio of equivalent yield load; $ \eta $max—Increase ratio of peak load. 表 5 不同截面形式混凝土组合柱轴压试验主要结果
Table 5. Main results of concrete composite columns with different section forms under axial compression load
Specimen Nmax/kN Ny/kN Nmax/ Ny Nmax-a/kN Ny-a/kN μa $ \eta $/% Failure mode CFST-A 803.02 688.53 1.17 800.38 673.60 2.93 — Softening CFST-B 797.73 658.66 1.21 CFFT-1-A 454.41 201.53 2.25 428.49 215.47 4.91 — Brittle failure CFFT-1-B 402.56 229.40 1.75 CFFT-2-A 620.42 315.04 1.97 606.75 325.32 3.30 41.60 CFFT-2-B 593.07 335.60 1.77 CFFT-3-A 827.34 432.45 1.91 835.77 414.89 4.11 95.05 CFFT-3-B 844.20 397.32 2.12 SCFC-1-A 1002.60 839.20 1.19 978.24 806.00 3.13 — Ductile failure SCFC-1-B 953.87 772.79 1.23 SCFC-2-A 1093.48 929.99 1.18 1097.08 885.32 4.78 12.15 SCFC-2-B 1100.69 840.65 1.31 SCFC-3-A 1309.79 1019.08 1.29 1298.56 991.67 3.31 32.74 SCFC-3-B 1287.33 964.26 1.34 Notes: Nmax-a—Mean value of peak load for specimens with same parameters; Ny-a—Mean value of equivalent yield load for specimens with same parameters; μa—Average ductility coefficient; $ \eta $—Peak load increase ratio. 表 6 T-SCFC柱轴压试验主要结果
Table 6. Main results of T-SCFC columns under axial compression load
Specimen NTmax/kN NTy/kN NTmax/ NTy NTmax-a/kN NTy-a/kN μT-a ηTmax/% ηTy/% T-SCFC-1-A 4330.79 3431.66 1.26 4255.69 3528.83 2.59 — — T-SCFC-1-B 4180.59 3626 1.15 T-SCFC-2-A 5044 3739 1.35 5042 3668.41 3.74 18.48 3.96 T-SCFC-2-B 5040 3597.82 1.40 T-SCFC-3-A 5360 4145.16 1.29 5316.50 4037.08 3.52 24.93 14.40 T-SCFC-3-B 5273 3929 1.34 Notes: NTmax—Peak load capacity of T-SCFC; NTy—Equivalent yield load of T-SCFC; NTmax-a—Mean value of peak load for specimens with same parameters; NTy-a—Mean value of equivalent yield load for specimens with same parameters; μT-a—Average ductility coefficient; ηTmax-Peak load increase ratio; ηTy—Increase ratio of equivalent yield load. 表 7 混凝土塑性损伤参数取值
Table 7. Concrete damaged plasticity parameter values
$ \psi $ $ \varepsilon $ ${ { {\sigma _{{\rm{b0}}} } } \mathord{\left/{\vphantom { { {\sigma _{b0} } } { {\sigma _{c0} } } }} \right.} { {\sigma _{{\rm{c0}}} } } }$ ${K_{\rm{c}}}$ $ \mu $ 30 0.1 1.16 0.6667 0.0005 Notes: $ \psi $—Dilatancy angle; $ \varepsilon $—Flow potential eccentricity; σb0/σc0—Ratio of initial equibiaxial compressive yield stress to initial uniaxial compressive yield stress; Kc—Ratio of the second stress invariant on the tensile meridian; μ—Viscosity parameter. 表 8 GFRP管模型参数
Table 8. Model parameters of GFRP tube
Thickness/mm 1 2 3 E1/GPa 81.13 62.33 65.17 E2=E3/GPa 6.63 4.57 3.46 ν12=ν13 0.33 0.33 0.33 ν23 0.35 0.32 0.33 G12= G13/GPa 6.5 6.5 6.5 G23/GPa 2.24 1.54 1.17 表 9 T-SCFC数值模拟结果与试验对比
Table 9. Comparison of numerical simulation and experimental results of T-SCFC
Specimen NTmax-a/kN NTmax-F/kN NTmax-a /NTmax-F T-SCFC-1-A/B 4255.69 4419.39 0.96 T-SCFC-2-A/B 5042.00 5002.74 1.01 T-SCFC-3-A/B 5316.50 5590.95 0.95 Note: NTmax-F—Peak load of numerical simulation. 表 10 T-SCFC数值试件基本参数
Table 10. Basic parameters of numerical specimens of T-SCFC
Numerical specimen fcu/MPa ts/mm T-SCFC-40-2.5 40 2.5 T-SCFC-40-3.5 40 3.5 T-SCFC-40-4.5 40 4.5 T-SCFC-40-5.5 40 5.5 T-SCFC-30-4.5 30 4.5 T-SCFC-50-4.5 50 4.5 T-SCFC-60-4.5 60 4.5 Notes: The naming format of T-SCFC specimens is “T-SCFC-x-y”, x, y represent core concrete strength and wall thickness of steel tube respectively; fcu—Core concrete strength. 表 11 钢管壁厚对T-SCFC试件承载力的影响
Table 11. Influence of wall thickness of steel tube on bearing capacity of T-SCFC specimens
Specimen Ny/kN Nmax/kN ηy/% ηmax/% T-SCFC-40-2.5 2085.40 3511.92 — — T-SCFC-40-3.5 2539.99 3689.89 21.80 5.07 T-SCFC-40-4.5 3138.71 4247.65 50.51 20.95 T-SCFC-40-5.5 3479.03 4759.08 66.83 35.51 表 12 核心混凝土强度对T-SCFC试件承载力的影响
Table 12. Influence of core concrete strength on bearing capacity of T-SCFC specimens
Specimen Ny/kN Nmax/kN ηy/% ηmax/% T-SCFC-30-4.5 2971.21 4260.06 — — T-SCFC-40-4.5 3138.71 4247.84 5.64 −0.29 T-SCFC-50-4.5 3220.93 4444.46 8.40 4.33 T-SCFC-60-4.5 3334.59 4456.23 12.23 4.60 -
[1] 郝际平, 孙晓岭, 薛强, 等. 绿色装配式钢结构建筑体系研究与应用[J]. 工程力学, 2017, 34(1):1-13.HAO Jiping, SUN Xiaoling, XUE Qiang, et al. Research and application of green prefabricated steel structure building system[J]. Engineering Mechanics,2017,34(1):1-13(in Chinese). [2] 孙晓岭, 郝际平, 薛强, 等. 壁式钢管混凝土柱抗震性能试验研究[J]. 建筑结构学报, 2018, 39(6):92-101.SUN Xiaoling, HAO Jiping, XUE Qiang, et al. Experimental study on seismic performance of wall concrete filled steel tubular columns[J]. Journal of Building Structures,2018,39(6):92-101(in Chinese). [3] 程杰, 齐玉军, 谢志锦. 玻璃纤维增强聚合物复合材料约束壁式钢管混凝土短柱轴压性能试验[J]. 复合材料学报, 2021, 38(6):1825-1837.CHENG Jie, QI Yujun, XIE Zhijin. Experiment on axial compression performance of glass fiber reinforced polymer-walled concrete-filled steel tube columns[J]. Acta Materiae Compositae Sinica,2021,38(6):1825-1837(in Chinese). [4] XIONG Q, CHEN Z, ZHANG W, et al. Compressive behaviour and design of L-shaped columns fabricated using concrete-filled steel tubes[J]. Engineering Structures,2017,152:758-770. [5] WANG F C, HAN L H. Analytical behavior of special-shaped CFST stub columns under axial compression[J]. Thin-Walled Structures,2018,129:404-417. [6] 叶列平, 冯鹏. FRP在工程结构中的应用与发展[J]. 土木工程学报, 2006, 39(3):24-36. doi: 10.3321/j.issn:1000-131X.2006.03.004YE Lieping, FENG Peng. Applications and development of fiber-reinforced polymer in engineering structures[J]. China Civil Engineering Journal,2006,39(3):24-36(in Chinese). doi: 10.3321/j.issn:1000-131X.2006.03.004 [7] 程实. 配置复材管内约束的方钢管混凝土柱轴压及抗震性能研究[D]. 北京: 清华大学, 2016.CHENG Shi. Research on axial compression and seismic performance of concrete filled square steel tubular columns with composite tube constraints [D]. Beijing: Tsinghua University, 2016 (in Chinese). [8] 张冰, 魏威, 冯贵森, 等. 纤维缠绕角度对GFRP约束混凝土短柱轴压性能的影响[J]. 建筑结构学报, 2019, 40(S1):192-199.ZHANG Bing, WEI Wei, FENG Guisen, et al. Effect of fiber winding angle on axial compression performance of GFRP confined concrete short columns[J]. Journal of Building Structures,2019,40(S1):192-199(in Chinese). [9] 国家市场监督管理总局. 金属材料拉伸试验第1部分: 室温试验方法: BG/T 228.1—2010[S]. 北京: 中国标准出版社, 2011.State Administration for Market Regulation. Tensile test of metal materials Part 1: Room temperature test method: BG/T 228.1—2010[S]. Beijing: China Standard Press, 2011 (in Chinese). [10] ASTM. Standard test method for apparent hoop tensile strength of plastic or reinforced plastic pipe by split disk method: ASTM D 2290—2012[S]. US: American Society for Testing and Materials, 2012. [11] 国家市场监督管理总局. 纤维增强热固性塑料管轴向压缩性能试验方法: GB/T 5350—2005[S]. 北京: 中国标准出版社, 2005.State Administration for Market Regulation. Test method for axial compression properties of fiber reinforced thermosetting plastic pipes: GB/T 5350—2005[S]. Beijing: China Standard Press, 2005 (in Chinese). [12] 中华人民共和国住房和城乡建设部. 普通混凝土力学性能试验方法标准: GB/T 50081—2019[S]. 北京: 中国建筑工业出版社, 2019.Ministry of Housing and Urban-Rural Development of the People's Republic of China. Standard for test methods of mechanical properties of ordinary concrete: GB/T 50081—2019[S]. Beijing: China Construction Industry Press, 2019 (in Chinese). [13] 郭莹, 许天祥, 刘界鹏. 圆CFRP-钢复合管约束高强混凝土短柱轴压试验研究[J]. 建筑结构学报, 2019, 40(5):124-131.GUO Ying, XU Tianxiang, LIU Jiepeng. Experimental study on axial compression of circular CFRP-steel composite tube confined high strength concrete short columns[J]. Journal of Architectural Structures,2019,40(5):124-131(in Chinese). [14] 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.FENG Peng, QIANG Hanlin, YE Lieping. The definition and discussion of 'yield point' of materials, components and structures[J]. Engineering Mechanics,2017,34(3):36-46(in Chinese). [15] WANG X X, QI Y J, SUN Y L, et al. Compressive behavior of composite concrete columns with encased FRP confined concrete cores[J]. Sensors,2019,19(8):1792. [16] 高鹏, 赵元鸿, 洪丽, 等. 圆角半径对碳纤维增强聚合物复合材料布约束型钢混凝土矩形短柱轴压性能的影响[J]. 复合材料学报, 2020, 37(4):775-785.GAO Peng, ZHAO Yuanhong, HONG Li, et al. The effect of fillet radius on axial compression performance of carbon fiber reinforced polymer composite cloth confined steel reinforced concrete rectangular short columns[J]. Journal of Composite Materials,2020,37(4):775-785(in Chinese). [17] SCHNEIDER S P. Axially loaded concrete-filled steel tubes[J]. Journal of Structural Engineering,1998,119(10):1125-1138. [18] 张伟, 唐站站, 杨艳. 等. 复合受力模式下 CFRP-混凝土界面剥离分析方法[J]. 建筑结构学报. https://doi.org/10.14006/j.jzjgxb.2020.0703.ZHANG Wei, TANG Zhanzhan, YANG Yan, et al. Analysis method of CFRP-concrete interface debonding under combined stress mode[J]. Journal of Architectural Structures.https://doi.org/10.14006/j.jzjgxb.2020.0703 (in Chinese). [19] GUADES E, ARAVINTHAN T, ISLAM M. Characterisation of the mechanical properties of pultruded fibre-reinforced polymer tube[J]. Materials & Design,2014,63:305-315. [20] TENG J G, HU Y M. Behaviour of FRP-jacketed circular steel tubes and cylindrical shells under axial compression[J]. Construction & Building Materials,2007,21(4):827-838. [21] 方小丹, 林斯嘉. 复式钢管高强混凝土柱轴压试验研究[J]. 建筑结构学报, 2014, 35(4):236-245.FANG Xiaodan, LIN Sijia. Experimental study on axial compression of composite high strength concrete filled steel tubular columns[J]. Journal of Building Structures,2014,35(4):236-245(in Chinese). [22] 鲁国昌, 叶列平, 杨才千, 等. FRP管约束混凝土的轴压应力-应变关系研究[J]. 工程力学, 2006(9):98-103. doi: 10.3969/j.issn.1000-4750.2006.09.017LU Guochang, YE Lieping, YANG Caiqian, et al. Research on axial compression stress-strain relationship of FRP tube confined concrete[J]. Engineering Mechanics,2006(9):98-103(in Chinese). doi: 10.3969/j.issn.1000-4750.2006.09.017 [23] LI B B, JIANG J F, XIONG H B, et al. Improved concrete plastic-damage model for FRP-confined concrete based on true tri-axial experiment[J]. Composite Structures,2021,269:114051. [24] 韩林海, 陶忠. 方钢管混凝土轴压力学性能的理论分析与试验研究[J]. 土木工程学报, 2001(2):17-25. doi: 10.3321/j.issn:1000-131X.2001.02.004HAN Linhai, TAO Zhong. Theoretical analysis and experimental study on mechanical properties of concrete filled square steel tubular under axial compression[J]. Journal of Civil Engineering,2001(2):17-25(in Chinese). doi: 10.3321/j.issn:1000-131X.2001.02.004 [25] GRAY P J, MCCARTHY C T. An analytical model for the prediction of through-thickness stiffness in tension-loaded composite bolted joints[J]. Composite Structures,2012,94(8):2450-2459. doi: 10.1016/j.compstruct.2012.02.011 [26] EGAN B, MCCARTHY C T, MCCARTHY M A, et al. Stress analysis of single-bolt, single-lap, countersunk composite joints with variable bolt-hole clearance[J]. Composite Structures,2012,94(3):1038-1051. doi: 10.1016/j.compstruct.2011.10.004 [27] 刘万雷, 常新龙, 张晓军, 等. 基于改进Hashin准则的复合材料低速冲击损伤研究[J]. 振动与冲击, 2016, 35(12):209-214.LIU Wanlei, CHANG Xinlong, ZHANG Xiaojun, et al. Research on low-speed impact damage of composites based on improved Hashin criterion[J]. Vibration and Impact,2016,35(12):209-214(in Chinese).