Effect of marine atmosphere on the bond behaviour of CFRP-steel interface
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摘要: 为研究长期海洋大气环境作用对碳纤维增强树脂复合材料(CFRP)-钢界面粘结性能的影响,设计并制作了36个CFRP-钢板双搭接试件,采用盐雾沉降量1~2 mL/80 (cm2·h)的盐雾箱来模拟海洋大气环境。对试件进行了疲劳加载后的静力拉伸试验,分析了环境作用时间(30、180、360天)、长期持续荷载和硅烷表面处理方式对CFRP-钢界面破坏模式和承载力的影响。研究结果表明:随着海洋大气环境作用时间增加,CFRP-钢双面搭接节点由胶层内破坏伴随CFRP层离破坏逐渐向钢-胶界面粘结失效转变。暴露360天后极限承载力最大下降了15.72%。硅烷表面处理对CFRP-钢界面耐久性提升作用较小。持续荷载导致短期环境作用下(30天)极限承载力下降了18.39%,但对长期环境作用影响很小,高应力预加疲劳导致CFRP-钢界面极限承载力最大下降了26.6%。采用Hart-Smith模型对CFRP-钢界面极限承载力进行计算,发现长期环境作用后的承载力预测值和试验值误差超过了30%。在考虑破坏模式变化对界面极限承载力的影响下进行了修正,将误差减小到最大为14.04%。Abstract: To investigate the effect of long-term marine atmosphere on the bond behaviour of carbon fibre reinforced polymer (CFRP)-steel interface, 36 CFRP-steel plate double-lap joint specimens were designed and fabri-cated. A salt spray box with a salt spray deposition volume of 1-2 mL/80 (cm2·h) was used to simulate the marine atmospheric environment. Fatigue and static tensile tests were carried out successively. The effects of environmental exposure time (30, 180, 360 days), long-term sustained load and silane surface treatment on the failure mode and ultimate bearing capacity of the CFRP-steel interface were analyzed. The results show that the failure mode of CFRP-steel interface gradually changes from cohesive failure and CFRP delamination to steel-adhesive interfacial debonding with the increase of exposure time to marine atmosphere. The long-term marine atmosphere effects cause significant degradation of the CFRP-steel interface bond performance, and the ultimate bearing capacity decreases by a maximum of 15.72% after 360 days of exposure. Silane surface treatment has little effect on improving the durability of CFRP-steel interface. The sustained load causes the ultimate bearing capacity to decrease by 18.39% under the short-term environmental action (30 days) while having little effect on the long-term environmental action. The high stress preload fatigue resulted in a maximum decrease of 26.6% in the ultimate bearing capacity. The Hart-Smith model was used to calculate the ultimate bearing capacity of the CFRP-steel interface, and it is found that the error between the predicted and experimental values of ultimate bearing capacity after long-term environmental action exceeds 30%. After considering the influence of failure mode change on the ultimate bearing capacity, the error is reduced to a maximum of 14.04%.
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Key words:
- marine atmosphere /
- CFRP /
- steel plate /
- interfacial bond behaviour /
- double-lap joint specimens
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表 1 材料性能
Table 1. Mechanical properties
Material Thickness/mm Elastic modulus/GPa Yield strength/MPa Tensile strength/MPa Elongation at
break/%Steel plate 5 187 335 495 17 CFRP laminate 1.4 210 − 3300 1.4 CFRP sheet 0.167 280 − 3603 1.8 Adhesive 0.5 2.48 − 35.52 2.6 Note: CFRP—Carbon fibre reinforced polymer. 表 2 试件参数和试验结果
Table 2. Summary of test program and results
Specimen CFRP type Exposure time Sustained load/kN Surface treatment Fatigue load range/kN Ultimate load carrying capacity/kN SL-F0.2-30 Sheet 30 days 18.2 – 1.82-18.20 87.99 SL-F0.5-30 Sheet 18.2 – 4.56-45.56 Failed at 16233 cycles SS-F0.2-30 Sheet – Silane treatment 1.88-18.82 111.80 SS-F0.5-30 Sheet – Silane treatment 4.71-47.05 Failed at 29162 cycles SLS-F0.2-30 Sheet 18.8 Silane treatment 1.88-18.82 91.24 SLS-F0.5-30 Sheet 18.8 Silane treatment 4.71-47.05 Failed at 11119 cycles LL-F0.2-30 Laminate 18.0 – 1.80-18.00 122.10 LL-F0.5-30 Laminate 18.0 – 4.50-45.00 89.60 LS-F0.2-30 Laminate – Silane treatment 1.85-18.53 —a LS-F0.5-30 Laminate – Silane treatment 4.63-46.33 112.00 LLS-F0.2-30 Laminate 18.5 Silane treatment 1.85-18.53 121.60 LLS-F0.5-30 Laminate 18.5 Silane treatment 4.63-46.33 93.08 SL-F0.2-180 Sheet 180 days 18.2 – 1.82-18.20 82.05 SL-F0.5-180 Sheet 18.2 – 4.56-45.56 Failed at 14097 cycles SS-F0.2-180 Sheet – Silane treatment 1.88-18.82 81.49 SS-F0.5-180 Sheet – Silane treatment 4.71-47.05 Failed at 10513 cycles SLS-F0.2-180 Sheet 18.8 Silane treatment 1.88-18.82 84.83 SLS-F0.5-180 Sheet 18.8 Silane treatment 4.71-47.05 Failed at 29162 cycles LL-F0.2-180 Laminate 18.0 – 1.80-18.00 —a LL-F0.5-180 Laminate 18.0 – 4.50-45.00 —a LS-F0.2-180 Laminate – Silane treatment 1.85-18.53 —a LS-F0.5-180 Laminate – Silane treatment 4.63-46.33 —a LLS-F0.2-180 Laminate 18.5 Silane treatment 1.85-18.53 —a LLS-F0.5-180 Laminate 18.5 Silane treatment 4.63-46.33 —a SL-F0.2-360 Sheet 360 days 18.2 – 1.82-18.20 —a SL-F0.5-360 Sheet 18.2 – 4.56-45.56 Failed at 12830 cycles SS-F0.2-360 Sheet – Silane treatment 1.88-18.82 79.86 SS-F0.5-360 Sheet – Silane treatment 4.71-47.05 Failed at 15485 cycles SLS-F0.2-360 Sheet 18.8 Silane treatment 1.88-18.82 78.42 SLS-F0.5-360 Sheet 18.8 Silane treatment 4.71-47.05 Failed at 12712 cycles LL-F0.2-360 Laminate 18.0 – 1.80-18.00 —a LL-F0.5-360 Laminate 18.0 – 4.50-45.00 —b LS-F0.2-360 Laminate – Silane treatment 1.85-18.53 —a LS-F0.5-360 Laminate – Silane treatment 4.63-46.33 —b LLS-F0.2-360 Laminate 18.5 Silane treatment 1.85-18.53 —b LLS-F0.5-360 Laminate 18.5 Silane treatment 4.63-46.33 —b Notes: SL—CFRP sheet specimen with sustained load applied; SS—CFRP sheet specimen with silane treatment; SLS—CFRP sheet specimen with sustained load applied and silane treatment; LL—CFRP laminate specimen with sustained load applied; LS—CFRP laminate specimen with silane treatment; LLS—CFRP laminate specimen with sustained load applied and silane treatment. F0.2 and F0.5—Specimen subjected to 0.2 times and 0.5 times preloaded fatigue load ratio respectively; 30, 180 and 360—30, 180 and 360 days of exposure in the marine atmosphere respectively; a and b—Fracture of the specimen at the end steel plate during static loading and fatigue loading. 表 3 各阶段钢-胶界面剥离面积
Table 3. Area of steel-adhesive interface debonding at each stage
Specimen Area after
30 days of
exposure/mm2Area ratio after
30 days of
exposure/%Area after
180 days of
exposure/mm2Area ratio after
180 days of
exposure/%Area after
360 days of
exposure/mm2Area ratio after
360 days of
exposure/%SS-F0.2 1305.92 26.12 2668.90 53.38 2250.27 45.01 SLS-F0.2 1500.99 30.02 2972.49 59.45 2360.00 47.20 -
[1] STEPHENS R I, FATEMI A, STEPHENS R R, et al. Metal fatigue in engineering[M]. New York: John Wiley and Sons, 2000. [2] TENG J G, YU T, FERNANDO D. Strengthening of steel structures with fiber-reinforced polymer composites[J]. Journal of Constructional Steel Research,2012,78:131-143. doi: 10.1016/j.jcsr.2012.06.011 [3] ZHAO X L. FRP-strengthened metallic structures[M]. Boca Raton: CRC Press, Taylor & Francis Group, 2013. [4] YU Q Q, WU Y F. Fatigue retrofitting of cracked steel beams with CFRP laminates[J]. Composite Structures,2018,192:232-244. doi: 10.1016/j.compstruct.2018.02.090 [5] WANG H T, WU G. Crack propagation prediction of double-edged cracked steel beams strengthened with FRP plates[J]. Thin-Walled Structures,2018,127:459-468. doi: 10.1016/j.tws.2018.02.018 [6] HU L L, FENG P, ZHAO X L. Fatigue design of CFRP strengthened steel members[J]. Thin-Walled Structures,2017,119:482-498. doi: 10.1016/j.tws.2017.06.029 [7] COLOMBI P, FAVA G. Experimental study on the fatigue behaviour of cracked steel beams repaired with CFRP plates[J]. Engineering Fracture Mechanics,2015,145:128-142. doi: 10.1016/j.engfracmech.2015.04.009 [8] 李安邦, 徐善华. 锈蚀对钢板表面特性及CFRP板-锈蚀钢板界面黏结性能的影响[J]. 复合材料学报, 2022, 39(2):746-758. doi: 10.13801/j.cnki.fhclxb.20210422.001LI Anbang, XU Shanhua. Effect of corrosion on the surface properties of steel plate and interfacial bonding properties between CFRP plate and corroded steel plate[J]. Acta Materiae Compositae Sinica,2022,39(2):746-758(in Chinese). doi: 10.13801/j.cnki.fhclxb.20210422.001 [9] ZHAO X L, BAI Y, AL-MAHAIDI R, et al. Effect of dynamic loading and environmental conditions on the bond between CFRP and steel: State-of-the-art review[J]. Jour-nal of Composites for Construction,2014,18:A4013005. doi: 10.1061/(ASCE)CC.1943-5614.0000419 [10] YANG Y, SILVA M A G, BISCAIA H, et al. Bond durability of CFRP laminates-to-steel joints subjected to freeze-thaw[J]. Composite Structures,2019,212:243-258. doi: 10.1016/j.compstruct.2019.01.016 [11] YANG Y, BISCAIA H, SILVA M A G, et al. Monotonic and quasi-static cyclic bond response of CFRP-to-steel joints after salt fog exposure[J]. Composites Part B: Engineering,2019,168:532-549. doi: 10.1016/j.compositesb.2019.03.066 [12] WANG Y, LI J, DENG J, et al. Bond behaviour of CFRP/steel strap joints exposed to overloading fatigue and wetting/drying cycles[J]. Engineering Structures,2018,172:1-12. doi: 10.1016/j.engstruct.2018.05.112 [13] NGUYEN T C, BAI Y, ZHAO X L, et al. Durability of steel/CFRP double strap joints exposed to sea water, cyclic temperature and humidity[J]. Composite Structures,2012,94(5):1834-1845. doi: 10.1016/j.compstruct.2012.01.004 [14] BORRIE D, LIU H B, ZHAO X L, et al. Bond durability of fatigued CFRP-steel double-lap joints pre-exposed to marine environment[J]. Composite Structures,2015,131:799-809. doi: 10.1016/j.compstruct.2015.06.021 [15] DAWOOD M, RIZKALLA S. Environmental durability of a CFRP system for strengthening steel structures[J]. Construction and Building Materials,2010,24:1682-1689. doi: 10.1016/j.conbuildmat.2010.02.023 [16] WANG Y, ZHENG Y, LI J, et al. Experimental study on tensile behaviour of steel plates with centre hole strengthened by CFRP plates under marine environment[J]. International Journal of Adhesion and Adhesives,2018,84:18-26. doi: 10.1016/j.ijadhadh.2018.01.017 [17] Committee MT-006. Mechanical testing of metals: Methods of tensile testing of metals: AS 1391—2007[S]. Sydney: Standards Australia, 2007. [18] American Society of Testing Materials International. Standard test method for tensile properties of polymer matrix composite materials: D 3039/D 3039 M-08[S]. West Conshohocken: American Society of Testing Materials, 2008. [19] American Society of Testing Materials International. Standard test method for tensile properties of plastics: D 638-08[S]. West Conshohocken: American Society of Testing Materials, 2008. [20] YU Q Q, GU X L, ZHAO X L, et al. Characterization of model uncertainty of adhesively bonded CFRP-to-steel joints[J]. Composite Structures,2019,215:150-165. doi: 10.1016/j.compstruct.2019.02.045 [21] 中国国家标准化管理委员会. 聚合物基复合材料疲劳性能测试方法 第1部分: 通则: GB/T 35465.1—2017[S]. 北京: 中国标准出版社, 2017.Standardization Administration of the People’s Republic of China. Test method for fatigue properties of polymer matrix composite materials-Part 1: General principle: GB/T 35465.1-2017[S]. Beijing: Standards Press of China, 2017(in Chinese). [22] YU Q Q, GAO R X, GU X L, et al. Bond behavior of CFRP-steel double-lap joints exposed to marine atmosphere and fatigue loading[J]. Engineering Structures,2018,175:76-85. doi: 10.1016/j.engstruct.2018.08.012 [23] ZHAO X L, ZHANG L. State-of-the-art review on FRP strengthened steel structures[J]. Steel Construction,2007,29(8):1808-1823. [24] POWERS D A. Interaction of water with epoxy: No. SAND2009-4405[R]. Albuquerque: Sandia National Laboratories (SNL), 2009. [25] HART-SMITH L J. Adhesive-bonded double-lap joints: NAS1-11234[R]. California: NASA, 1973. [26] 高瑞鑫, 余倩倩. 养护阶段环境作用对结构黏胶力学性能影响[J]. 建筑结构学报, 2018, 39(S1):405-409. doi: 10.14006/j.jzjgxb.2018.S1.053GAO Ruixin, YU Qianqian. Effects of environmental expo-sure during curing stage on adhesive material properties[J]. Journal of Building Structures,2018,39(S1):405-409(in Chinese). doi: 10.14006/j.jzjgxb.2018.S1.053 [27] XIA S H, TENG J G. Behaviour of FRP-to-steel bonded joints[C]//CHEN J F, TENG J G. Proceedings of the international symposium on bond behaviour of FRP in structures (BBFS 2005). Hong Kong: International Institute for FRP in Construction, 2005: 419-426. [28] LIU M, DAWOOD M. Reliability analysis of adhesively bonded CFRP-to-steel double lap shear joint with thin outer adherends[J]. Construction and Building Materials,2017,141:52-63. doi: 10.1016/j.conbuildmat.2017.02.113