普通混凝土落锤冲击动态力学性能试验研究
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摘要
为研究普通混凝土材料的动态冲击力学性能,利用改进的落锤冲击试验装置,对C30混凝土圆柱体进行低速冲击试验。为降低落锤冲击惯性效应并获得稳定的加载速率,试验采用不同厚度的橡胶或海绵作为波形整形材料;采用20 mm厚橡胶时可消除惯性力影响,延长加载时间,使试件纵向应力趋于均匀分布,并实现恒定速率加载。试验结果表明:冲击荷载下混凝土破坏形态与静载下相同,动态增大系数(DIF)、极限应变与吸收能量随应变率增加而增加,在本文试验参数范围内应变率对混凝土应力-应变曲线形状影响较小。对已有混凝土动态力学性能试验结果进行统计和对比,验证了CEB2010规范公式偏于保守地描述了DIF与应变率的关系,且本文的研究结果填补了应变率10-1/s~100/s范围内试验数据。
In order to investigate the dynamic behavior of ordinary concrete under impact loading, the low-speed impact tests on C30 concrete cylindrical specimens were carried out by using an improved drop hammer test setup. The rubber and sponge with different thickness were used as shaper to reduce the impact inertia effect and obtain steady loading rate. The 20 mm thick rubber pad significantly reduced the inertia effect and prolonged the loading time duration. The longitudinal stress of the specimens tended to uniformly distribute and led to a constant loading rate. The test results show that the concrete failure mode under impact loading is the same as that under static loading. Furthermore, dynamic increase factor(DIF), ultimate strain and energy-absorption increase with the increase of strain rate. However, it is found that within the test parameters of this paper, the strain rate has little effect on the shape of stress-strain curves of concrete. Moreover, the dynamic tests on concrete from the literature were further summarized and compared. The formula recommended by CEB2010 can conservatively describe the relationship between DIF and strain rate. The results in this paper filled in the blank within the strain rate range of 10-1/s~100/s for the existing testing data.
In order to investigate the dynamic behavior of ordinary concrete under impact loading, the low-speed impact tests on C30 concrete cylindrical specimens were carried out by using an improved drop hammer test setup. The rubber and sponge with different thickness were used as shaper to reduce the impact inertia effect and obtain steady loading rate. The 20 mm thick rubber pad significantly reduced the inertia effect and prolonged the loading time duration. The longitudinal stress of the specimens tended to uniformly distribute and led to a constant loading rate. The test results show that the concrete failure mode under impact loading is the same as that under static loading. Furthermore, dynamic increase factor(DIF), ultimate strain and energy-absorption increase with the increase of strain rate. However, it is found that within the test parameters of this paper, the strain rate has little effect on the shape of stress-strain curves of concrete. Moreover, the dynamic tests on concrete from the literature were further summarized and compared. The formula recommended by CEB2010 can conservatively describe the relationship between DIF and strain rate. The results in this paper filled in the blank within the strain rate range of 10-1/s~100/s for the existing testing data.
引文
[1]Abrams D A.Effect of rate of application of load on the compressive strength of concrete[J].ASTM J,1917,17(2):70-78.
[2]董毓利,谢和平.不同应变率下混凝土受压全过程的实验研究及其本构模型[J].水利学报,1997(7):72-77.DONG Yuli,XIE Heping.Experimental study and constitutive model on concrete under compression with different strain rate[J].Journal of Hydraulic Engineering,1997(7):72-77.
[3]张玉敏.不同应变率下混凝土力学性能的试验研究[D].北京:北京工业大学,2012.ZHANG Yumin.Experimental study of the mechanical properties of concrete under different strain rates[D].Beijing:Beijing University of Technology,2012.
[4]闫东明.混凝土动态力学性能试验与理论研究[D].大连:大连理工大学,2006.YAN Dongming.Experimental and theoretical study on the dynamic properties of concrete[D].Dalian:Dalian University of Technology,2006.
[5]肖诗云.混凝土率型本构模型及其在拱坝动力分析中的应用[D].大连:大连理工大学,2002.XIAO Shiyun.Rate-dependent constitutive model of concrete and its application to dynamic response of arch dams[D].Dalian:Dalian University of Technology,2002.
[6]Malvern L E,Tang T,Jenkins D A,et al.Dynamic compressive strength of cementitious materials[J].MRS Proceedings.Cambridge University Press,1985,64:119.
[7]Tang T,Malvern L E,Jenkins D A.Rate effects in uniaxial dynamic compression of concrete[J].Journal of Engineering Mechanics,1992,118(1):108-124.
[8]Ross C A,Tedesco J W,Kuennen S T.Effects of strain rate on concrete strength[J].Materials Journal,1995,92(1):37-47.
[9]严少华,段吉祥.高强混凝土SHPB试验研究[J].解放军理工大学学报(自然科学版),2000,1(3):6-9.YAN Shaohua,DUAN Jixiang.SHPB test on highstrength concrete[J].Journal of PLA University of Science and Technology(Natural Science),2000,1(3):6-9.
[10]胡时胜,王道荣,刘剑飞.混凝土材料动态力学性能的实验研究[J].工程力学,2001,18(5):115-118.HU Shisheng,WANG Daorong,LIU Jianfei.Experimental study of dynamic mechanical behavior of concrete[J].Engineering Mechanics,2001,18(5):115-118.
[11]张志刚,孔大庆,宫光明,等.高应变率下混凝土动态力学性能SHPB实验[J].解放军理工大学学报(自然科学版),2007,8(6):611-618.ZHANG Zhigang,KONG Daqing,GONG Guangming,et al.Dynamic mechanical behavior of concrete under high strain rate using SHPB[J].Journal of PLA University of Science and Technology(Natural Science),2007,8(6):611-618.
[12]何远明,霍静思,陈柏生,等.高温下混凝土SHPB动态力学性能试验研究[J].工程力学,2012,29(9):200-208.HE Yuanming,HUO Jingsi,CHEN Baisheng,et al.Impact tests on dynamic behavior of concrete at elevated temperatures[J].Engineering Mechanics,2012,29(9):200-208.
[13]Watstein D.Effect of straining rate on the compressive strength and elastic properties of concrete[J].Journal of the American Concrete Institute.1953,49(4):729-744.
[14]Hughes B P,Gregory R.Concrete subjected to high rates of loading in compression[J].Magazine of Concrete Research,1972,24(78):25-36.
[15]Hughes B P,Watson A J.Compressive strength and ultimate strain of concrete under impact loading[J].Magazine of Concrete Research,1978,30(105):189-199.
[16]Bischoff P H,Perry S H.Impact behavior of plain concrete loaded in uniaxial compression[J].Journal of Engineering Mechanics,1995,121(6):685-693.
[17]Bischoff P H,Perry S H.Compressive behaviour of concrete at high strain rates[J].Materials and Structures,1991,24(6):425-450.
[18]Cotsovos D M,Pavlovi?M N.Numerical investigation of concrete subjected to compressive impact loading.Part 1:A fundamental explanation for the apparent strength gain at high loading rates[J].Computers&Structures,2008,86(1):145-163.
[19]GB/T 50081—2002,普通混凝土力学性能试验方法标准[S].GB/T 50081—2002,Standard for test method of mechanical properties on ordinary concrete[S].
[20]LI G,LIU D.Low strain rate testing based on drop weight impact tester[J].Experimental Techniques,2015,39(5):30-35.
[21]王礼立.应力波基础[M].北京:国防工业出版社,2010.WANG Lili.Foundation of stress waves[M].Beijing:National Defense Industry Press,2010.
[22]Atchley B L,Furr H L.Strength and energy absorption capablities of plain concrete under dynamic and static loadings[J].Journal Proceedings,1967,64(11):745-756.
[23]Code CEB—FIP 2010,Fib model code for concrete structures 2010[S].
[24]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.
[25]孟一,易伟建.混凝土圆柱体试件在低速冲击下动力效应的研究[J].振动与冲击,2011,30(3):205-210.MENG Yi,YI Weijian.Dynamic behavior of concrete cylinder specimens under low velocity impact[J].Journal of Vibration and Shock,2011,30(3):205-210.
[2]董毓利,谢和平.不同应变率下混凝土受压全过程的实验研究及其本构模型[J].水利学报,1997(7):72-77.DONG Yuli,XIE Heping.Experimental study and constitutive model on concrete under compression with different strain rate[J].Journal of Hydraulic Engineering,1997(7):72-77.
[3]张玉敏.不同应变率下混凝土力学性能的试验研究[D].北京:北京工业大学,2012.ZHANG Yumin.Experimental study of the mechanical properties of concrete under different strain rates[D].Beijing:Beijing University of Technology,2012.
[4]闫东明.混凝土动态力学性能试验与理论研究[D].大连:大连理工大学,2006.YAN Dongming.Experimental and theoretical study on the dynamic properties of concrete[D].Dalian:Dalian University of Technology,2006.
[5]肖诗云.混凝土率型本构模型及其在拱坝动力分析中的应用[D].大连:大连理工大学,2002.XIAO Shiyun.Rate-dependent constitutive model of concrete and its application to dynamic response of arch dams[D].Dalian:Dalian University of Technology,2002.
[6]Malvern L E,Tang T,Jenkins D A,et al.Dynamic compressive strength of cementitious materials[J].MRS Proceedings.Cambridge University Press,1985,64:119.
[7]Tang T,Malvern L E,Jenkins D A.Rate effects in uniaxial dynamic compression of concrete[J].Journal of Engineering Mechanics,1992,118(1):108-124.
[8]Ross C A,Tedesco J W,Kuennen S T.Effects of strain rate on concrete strength[J].Materials Journal,1995,92(1):37-47.
[9]严少华,段吉祥.高强混凝土SHPB试验研究[J].解放军理工大学学报(自然科学版),2000,1(3):6-9.YAN Shaohua,DUAN Jixiang.SHPB test on highstrength concrete[J].Journal of PLA University of Science and Technology(Natural Science),2000,1(3):6-9.
[10]胡时胜,王道荣,刘剑飞.混凝土材料动态力学性能的实验研究[J].工程力学,2001,18(5):115-118.HU Shisheng,WANG Daorong,LIU Jianfei.Experimental study of dynamic mechanical behavior of concrete[J].Engineering Mechanics,2001,18(5):115-118.
[11]张志刚,孔大庆,宫光明,等.高应变率下混凝土动态力学性能SHPB实验[J].解放军理工大学学报(自然科学版),2007,8(6):611-618.ZHANG Zhigang,KONG Daqing,GONG Guangming,et al.Dynamic mechanical behavior of concrete under high strain rate using SHPB[J].Journal of PLA University of Science and Technology(Natural Science),2007,8(6):611-618.
[12]何远明,霍静思,陈柏生,等.高温下混凝土SHPB动态力学性能试验研究[J].工程力学,2012,29(9):200-208.HE Yuanming,HUO Jingsi,CHEN Baisheng,et al.Impact tests on dynamic behavior of concrete at elevated temperatures[J].Engineering Mechanics,2012,29(9):200-208.
[13]Watstein D.Effect of straining rate on the compressive strength and elastic properties of concrete[J].Journal of the American Concrete Institute.1953,49(4):729-744.
[14]Hughes B P,Gregory R.Concrete subjected to high rates of loading in compression[J].Magazine of Concrete Research,1972,24(78):25-36.
[15]Hughes B P,Watson A J.Compressive strength and ultimate strain of concrete under impact loading[J].Magazine of Concrete Research,1978,30(105):189-199.
[16]Bischoff P H,Perry S H.Impact behavior of plain concrete loaded in uniaxial compression[J].Journal of Engineering Mechanics,1995,121(6):685-693.
[17]Bischoff P H,Perry S H.Compressive behaviour of concrete at high strain rates[J].Materials and Structures,1991,24(6):425-450.
[18]Cotsovos D M,Pavlovi?M N.Numerical investigation of concrete subjected to compressive impact loading.Part 1:A fundamental explanation for the apparent strength gain at high loading rates[J].Computers&Structures,2008,86(1):145-163.
[19]GB/T 50081—2002,普通混凝土力学性能试验方法标准[S].GB/T 50081—2002,Standard for test method of mechanical properties on ordinary concrete[S].
[20]LI G,LIU D.Low strain rate testing based on drop weight impact tester[J].Experimental Techniques,2015,39(5):30-35.
[21]王礼立.应力波基础[M].北京:国防工业出版社,2010.WANG Lili.Foundation of stress waves[M].Beijing:National Defense Industry Press,2010.
[22]Atchley B L,Furr H L.Strength and energy absorption capablities of plain concrete under dynamic and static loadings[J].Journal Proceedings,1967,64(11):745-756.
[23]Code CEB—FIP 2010,Fib model code for concrete structures 2010[S].
[24]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.
[25]孟一,易伟建.混凝土圆柱体试件在低速冲击下动力效应的研究[J].振动与冲击,2011,30(3):205-210.MENG Yi,YI Weijian.Dynamic behavior of concrete cylinder specimens under low velocity impact[J].Journal of Vibration and Shock,2011,30(3):205-210.