低应变率下混凝土动态拉伸破坏尺寸效应细观模拟
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摘要
在混凝土静态破坏尺寸效应方面已取得了较完善的成果,而在动态破坏尺寸效应方面,包括其产生机制及对应的尺寸效应律的研究则非常匮乏。为探讨动态荷载作用下混凝土尺寸效应行为,从细观角度出发,结合混凝土细观结构特征,考虑动态加载下细观组分应变率效应的影响,建立了混凝土破坏行为研究的细观力学分析模型与方法。以双边缺口混凝土试件为例,对其在低应变率(10~(-5) s~(-1)～1 s~(-1))下混凝土动态拉伸破坏行为及尺寸效应进行细观数值模拟,并分析了应变率效应对动态破坏尺寸效应的影响。最后,结合应变率效应对强度及尺寸效应的影响规律—"强度增强效应"与"尺寸效应削弱效应",在静态破坏尺寸效应律的基础上,建立了混凝土拉伸强度的"静动态统一"尺寸效应理论公式,并验证了理论公式的准确性和合理性。
Great progresses have been made in static size effect of concretes, while few efforts have been conducted in dynamic size effect of concretes. Herein the study, in order to explore the size effect of concrete under dynamic loadings, considering concrete heterogeneities and the strain rate effect for the meso components, a meso-scale simulation method was built. Taking the double notched concrete specimens as examples, the dynamic tensile failure and the size effect of concrete under low strain rates from 10~(-5) s~(-1) to 1 s~(-1) were investigated using the meso-scale simulation method. The effect of strain rate on the size effect in tensile strength of concrete was also analyzed. Finally, based on the influencing mechanism of strain rate effect on dynamic strength and size effect, i.e. the enhancement of strength and weakening of size effect, a "static-dynamic unified size effect law" for dynamic tensile strength of concrete was established. The proposed size effect law was also calibrated by meso-scale simulation results.
Great progresses have been made in static size effect of concretes, while few efforts have been conducted in dynamic size effect of concretes. Herein the study, in order to explore the size effect of concrete under dynamic loadings, considering concrete heterogeneities and the strain rate effect for the meso components, a meso-scale simulation method was built. Taking the double notched concrete specimens as examples, the dynamic tensile failure and the size effect of concrete under low strain rates from 10~(-5) s~(-1) to 1 s~(-1) were investigated using the meso-scale simulation method. The effect of strain rate on the size effect in tensile strength of concrete was also analyzed. Finally, based on the influencing mechanism of strain rate effect on dynamic strength and size effect, i.e. the enhancement of strength and weakening of size effect, a "static-dynamic unified size effect law" for dynamic tensile strength of concrete was established. The proposed size effect law was also calibrated by meso-scale simulation results.
引文
[1]杜修力,金浏,李冬.混凝土与混凝土结构尺寸效应述评(Ⅰ):材料层次[J].土木工程学报,2017(9):28―45.Du Xiuli,Jin Liu,Li Dong.A state-of-the-art review on the size effect of concretes and concrete structures(I):concrete materials[J].China Civil Engineering Journal,2017(9):28―45.(in Chinese)
[2]杜修力,金浏,李冬.混凝土与混凝土结构尺寸效应述评(Ⅱ):构件层次[J].土木工程学报,2017,50(11):24―44.Du Xiuli,Jin Liu,Li Dong.A state-of-the-art review on the size effect of concretes and concrete structures(II):RC members[J].China Civil Engineering Journal,2017,50(11):24―44.(in Chinese)
[3]Wang X H,Zhang S R,Wang C,et al.Experimental investigation of the size effect of layered roller compacted concrete(RCC)under high-strain-rate loading[J].Construction&Building Materials,2018,165:45―57.
[4]Ba?ant Z P,Planas J.Fracture and size effect in concrete and other quasibrittle materials[M].CRC Press,1998:7―15.
[5]Weibull W.The phenomenon of rupture in solids[J].Proceedings of Royal Sweden Institute of Engineering Research,1939,153:1―55.
[6]Carpinteri A,Ferro G.Size effects on tensile fracture properties:a unified explanation based on disorder and fractality of concrete microstructure[J].Materials&Structures,1994,27(10):563―571.
[7]Li Q M,Meng H.About the dynamic strength enhancement of concrete-like materials in a split Hopkinson pressure bar test[J].International Journal of Solids&Structures,2003,40(2):343―360.
[8]Hao Y,Hao H,Jiang G P,et al.Experimental confirmation of some factors influencing dynamic concrete compressive strengths in high-speed impact tests[J].Cement&Concrete Research,2013,52(10):63―70.
[9]Hao Y,Hao H,Li Z X.Influence of end friction confinement on impact tests of concrete material at high strain rate[J].International Journal of Impact Engineering,2013,60(60):82―106.
[10]Hao Y,Hao H,Li Z X.Numerical analysis of lateral inertial confinement effects on impact test of concrete compressive material properties[J].International Journal of Protective Structures,2010,1(1):145―168.
[11]Hao H,Hao Y,Li J,et al.Review of the current practices in blast-resistant analysis and design of concrete structures[J].Advances in Structural Engineering,2016,19(8):1193―1223.
[12]Krauthammer T,Elfahal MM,Lim J,et al.Size effect for high strength concrete cylinders subjected to axial impact[J].International Journal of Impact Engineering,2003,28(9):1001―1016.
[13]Filho E D S S,Barbosa M T G.Dynamic size effect in normal-and high-strength concrete cylinders[J].ACIMaterials Journal,2005,102(2):77―85.
[14]Elfahal M M,Krauthammer T,Ohno T,et al.Size effect for normal strength concrete cylinders subjected to axial impact[J].International Journal of Impact Engineering,2005,31(4):461―481.
[15]Bindiganavile V,Banthia N.Size effects and the dynamic response of plain concrete[J].Journal of Materials in Civil Engineering,2006,18(4):485―491.
[16]胡伟华,邹荣华,彭刚,等.不同应变速率下混凝土吸能特性及尺寸效应的研究[J].长江科学院院报,2015,32(5):132―136.Hu Weihua,Zou Ronghua,Peng Gang,et al.Energy absorption characteristics and size effect of concrete under different strain rates[J].Journal of Yangtze River Scientific Research Institute,2015,32(5):132―136.(in Chinese)
[17]Li M,Hao H,Shi Y,et al.Specimen shape and size effects on the concrete compressive strength under static and dynamic tests[J].Construction&Building Materials,2018,161:84―93.
[18]Zhou X Q,Hao H.Modelling of compressive behaviour of concrete-like materials at high strain rate[J].International Journal of Solids&Structures,2008,45(17):4648―4661.
[19]Snozzi L,Caballero A,Molinari J F.Influence of the meso-structure in dynamic fracture simulation of concrete under tensile loading[J].Cement&Concrete Research,2011,41(11):1130―1142.
[20]Pedersen R R,Simone A.Mesoscopic modeling and simulation of the dynamic tensile behavior of concrete[J].Cement&Concrete Research,2013,50(7):74―87.
[21]Du X,Jin L,Ma G.Numerical simulation of dynamic tensile-failure of concrete at meso-scale[J].International Journal of Impact Engineering,2014,66(4):5―17.
[22]Jin L,Xu C,Han Y,et al.Effect of end friction on the dynamic compressive mechanical behavior of concrete under medium and low strain rates[J].Shock and Vibration,2016,2016:1―20.
[23]金浏,杜修力.加载速率对混凝土拉伸破坏行为影响的细观数值分析[J].工程力学,2015,32(8):42―49.Jin L,Du X.Meso-scale numerical analysis of the effect of loading rate on the tensile failure behavior of concrete[J].Engineering Mechanics,2015,32(8):42―49.(in Chinese)
[24]杜敏,金浏,李冬,等.骨料粒径对混凝土劈拉性能及尺寸效应影响的细观数值研究[J].工程力学,2017,34(9):54―63.Du M,Jin L,Li Dong,et al.Mesoscopic simulation study of the influence of aggregate size on mechanical properties and specimen size effect of concrete subjected to splitting tensile loading[J].Engineering Mechanics,2017,34(9):54―63.(in Chinese)
[25]Man H K,Mier J G M V.Size effect on strength and fracture energy for numerical concrete with realistic aggregate shapes[J].International Journal of Fracture,2008,154(1-2):61―72.
[26]Grassl P,Grégoire D,Solano L R,et al.Meso-scale modelling of the size effect on the fracture process zone of concrete[J].International Journal of Solids&Structures,2012,49(13):1818―1827.
[27]Wang X,Yang Z,Jivkov A P.Monte Carlo simulations of mesoscale fracture of concrete with random aggregates and pores:a size effect study[J].Construction&Building Materials,2015,80:262―272.
[28]Lee J,Fenves G L.Plastic-damage model for cyclic loading of concrete structures[J].Journal of Engineering Mechanics,1998,124(8):892―900.
[29]Lubliner J,Oliver J,Oller S,et al.A plastic-damage model for concrete[J].International Journal of Solids&Structures,1989,25(3):299―326.
[30]Dilger W H,Koch R,Kowalczyk R.Ductility of plain and confined concrete under different strain rates[J].Journal of the American Concrete Institute,1984,81(1):73―81.
[31]Bischoff P H,Perry S H.Compressive behaviour of concrete at high strain rates[J].Materials&Structures,1991,24(6):425―450.
[32]Cusatis G.Strain-rate effects on concrete behavior[J].International Journal of Impact Engineering,2011,38(4):162―170.
[33]Comite Euro-International D B.CEB-FIP model code1990[S].Trowbridge,Wiltshire,UK:Redwood Books,1993.
[34]Malvar L J,Ross C A.A review of strain rate effects for concrete in tension[J].ACI Materials Journal,1998,95(6):735―739.
[35]Yan D,Lin G.Dynamic properties of concrete in direct tension[J].Cement&Concrete Research,2006,36(7):1371―1378.
[2]杜修力,金浏,李冬.混凝土与混凝土结构尺寸效应述评(Ⅱ):构件层次[J].土木工程学报,2017,50(11):24―44.Du Xiuli,Jin Liu,Li Dong.A state-of-the-art review on the size effect of concretes and concrete structures(II):RC members[J].China Civil Engineering Journal,2017,50(11):24―44.(in Chinese)
[3]Wang X H,Zhang S R,Wang C,et al.Experimental investigation of the size effect of layered roller compacted concrete(RCC)under high-strain-rate loading[J].Construction&Building Materials,2018,165:45―57.
[4]Ba?ant Z P,Planas J.Fracture and size effect in concrete and other quasibrittle materials[M].CRC Press,1998:7―15.
[5]Weibull W.The phenomenon of rupture in solids[J].Proceedings of Royal Sweden Institute of Engineering Research,1939,153:1―55.
[6]Carpinteri A,Ferro G.Size effects on tensile fracture properties:a unified explanation based on disorder and fractality of concrete microstructure[J].Materials&Structures,1994,27(10):563―571.
[7]Li Q M,Meng H.About the dynamic strength enhancement of concrete-like materials in a split Hopkinson pressure bar test[J].International Journal of Solids&Structures,2003,40(2):343―360.
[8]Hao Y,Hao H,Jiang G P,et al.Experimental confirmation of some factors influencing dynamic concrete compressive strengths in high-speed impact tests[J].Cement&Concrete Research,2013,52(10):63―70.
[9]Hao Y,Hao H,Li Z X.Influence of end friction confinement on impact tests of concrete material at high strain rate[J].International Journal of Impact Engineering,2013,60(60):82―106.
[10]Hao Y,Hao H,Li Z X.Numerical analysis of lateral inertial confinement effects on impact test of concrete compressive material properties[J].International Journal of Protective Structures,2010,1(1):145―168.
[11]Hao H,Hao Y,Li J,et al.Review of the current practices in blast-resistant analysis and design of concrete structures[J].Advances in Structural Engineering,2016,19(8):1193―1223.
[12]Krauthammer T,Elfahal MM,Lim J,et al.Size effect for high strength concrete cylinders subjected to axial impact[J].International Journal of Impact Engineering,2003,28(9):1001―1016.
[13]Filho E D S S,Barbosa M T G.Dynamic size effect in normal-and high-strength concrete cylinders[J].ACIMaterials Journal,2005,102(2):77―85.
[14]Elfahal M M,Krauthammer T,Ohno T,et al.Size effect for normal strength concrete cylinders subjected to axial impact[J].International Journal of Impact Engineering,2005,31(4):461―481.
[15]Bindiganavile V,Banthia N.Size effects and the dynamic response of plain concrete[J].Journal of Materials in Civil Engineering,2006,18(4):485―491.
[16]胡伟华,邹荣华,彭刚,等.不同应变速率下混凝土吸能特性及尺寸效应的研究[J].长江科学院院报,2015,32(5):132―136.Hu Weihua,Zou Ronghua,Peng Gang,et al.Energy absorption characteristics and size effect of concrete under different strain rates[J].Journal of Yangtze River Scientific Research Institute,2015,32(5):132―136.(in Chinese)
[17]Li M,Hao H,Shi Y,et al.Specimen shape and size effects on the concrete compressive strength under static and dynamic tests[J].Construction&Building Materials,2018,161:84―93.
[18]Zhou X Q,Hao H.Modelling of compressive behaviour of concrete-like materials at high strain rate[J].International Journal of Solids&Structures,2008,45(17):4648―4661.
[19]Snozzi L,Caballero A,Molinari J F.Influence of the meso-structure in dynamic fracture simulation of concrete under tensile loading[J].Cement&Concrete Research,2011,41(11):1130―1142.
[20]Pedersen R R,Simone A.Mesoscopic modeling and simulation of the dynamic tensile behavior of concrete[J].Cement&Concrete Research,2013,50(7):74―87.
[21]Du X,Jin L,Ma G.Numerical simulation of dynamic tensile-failure of concrete at meso-scale[J].International Journal of Impact Engineering,2014,66(4):5―17.
[22]Jin L,Xu C,Han Y,et al.Effect of end friction on the dynamic compressive mechanical behavior of concrete under medium and low strain rates[J].Shock and Vibration,2016,2016:1―20.
[23]金浏,杜修力.加载速率对混凝土拉伸破坏行为影响的细观数值分析[J].工程力学,2015,32(8):42―49.Jin L,Du X.Meso-scale numerical analysis of the effect of loading rate on the tensile failure behavior of concrete[J].Engineering Mechanics,2015,32(8):42―49.(in Chinese)
[24]杜敏,金浏,李冬,等.骨料粒径对混凝土劈拉性能及尺寸效应影响的细观数值研究[J].工程力学,2017,34(9):54―63.Du M,Jin L,Li Dong,et al.Mesoscopic simulation study of the influence of aggregate size on mechanical properties and specimen size effect of concrete subjected to splitting tensile loading[J].Engineering Mechanics,2017,34(9):54―63.(in Chinese)
[25]Man H K,Mier J G M V.Size effect on strength and fracture energy for numerical concrete with realistic aggregate shapes[J].International Journal of Fracture,2008,154(1-2):61―72.
[26]Grassl P,Grégoire D,Solano L R,et al.Meso-scale modelling of the size effect on the fracture process zone of concrete[J].International Journal of Solids&Structures,2012,49(13):1818―1827.
[27]Wang X,Yang Z,Jivkov A P.Monte Carlo simulations of mesoscale fracture of concrete with random aggregates and pores:a size effect study[J].Construction&Building Materials,2015,80:262―272.
[28]Lee J,Fenves G L.Plastic-damage model for cyclic loading of concrete structures[J].Journal of Engineering Mechanics,1998,124(8):892―900.
[29]Lubliner J,Oliver J,Oller S,et al.A plastic-damage model for concrete[J].International Journal of Solids&Structures,1989,25(3):299―326.
[30]Dilger W H,Koch R,Kowalczyk R.Ductility of plain and confined concrete under different strain rates[J].Journal of the American Concrete Institute,1984,81(1):73―81.
[31]Bischoff P H,Perry S H.Compressive behaviour of concrete at high strain rates[J].Materials&Structures,1991,24(6):425―450.
[32]Cusatis G.Strain-rate effects on concrete behavior[J].International Journal of Impact Engineering,2011,38(4):162―170.
[33]Comite Euro-International D B.CEB-FIP model code1990[S].Trowbridge,Wiltshire,UK:Redwood Books,1993.
[34]Malvar L J,Ross C A.A review of strain rate effects for concrete in tension[J].ACI Materials Journal,1998,95(6):735―739.
[35]Yan D,Lin G.Dynamic properties of concrete in direct tension[J].Cement&Concrete Research,2006,36(7):1371―1378.