用户名: 密码: 验证码:
基于分形理论的混凝土统计损伤本构模型研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
由于混凝土材料具有原料丰富、耐久性好等优点,在建筑结构中得到广泛的使用。但混凝土材料不同于钢材等各向同性均质材料,它作为一种复合材料,在微细观上体现出明显的多相性、多孔性以及非均质性,而在宏观上又体现出力学性能的离散性和随机性,凡此种种对于建筑结构的受力以及抗震性能有着复杂的影响。与普通混凝土相比,超高强高性能混凝土中水泥浆体强度较大,甚至与骨料相当,表现出较高的脆性,或者是较强的均匀性,不过其力学性能的随机性和离散性仍旧无法避免。针对混凝土材料的上述力学性能,本文进行了如下研究:
     基于随机损伤研究领域常用的单轴受压随机损伤弹簧模型,引入Weibull分布以及对数正态分布的概率密度函数用以描述微元体弹簧的极限应变分布规律,通过对比分析建立了可用分维表示材料的均质度,并且同时适用于普通混凝土以及超高强高性能混凝土的单轴受压细观统计损伤本构模型;利用应变等效假设将经典损伤变量定义转化为损伤破坏过程中混凝土弹性模量的变化量与初始弹性模量的比值,通过混凝土CT无损扫描试验以及单轴压缩试验,确定了已建立模型中的参数。
     基于杜荣强提出的“损伤因子”,将建立的单轴应力状态下的损伤演化方程推演至多轴应力状态下,进而得到多轴应力状态下的细观统计损伤本构模型。将本文所提出的单轴以及多轴损伤本构模型与试验结果以及数值模拟算例进行对比分析发现,它们可以较为准确地反映混凝土的损伤演化规律。
     考虑到试验验证的需要,本文配制了三组不同强度等级的超高强高性能混凝土以及普通混凝土,简要介绍了超高强高性能混凝土配合比试验,分析了超高强高性能混凝土水胶比、胶凝材料用量以及粗骨料级配等参量对混凝土力学性能的影响;而后基于CT无损扫描试验、采用差分盒维数法研究了各强度等级混凝土的分形断裂特性,分析了以上各参量对断裂面分形维数的影响,并就其分形断裂机理作出了合理解释。
     本研究为深入研究超高强高性能混凝土的力学性能提供了一定的理论基础,有助于工程技术人员对混凝土内部组份之间的作用机理进行认识和理解,将为进一步研究混凝土细观损伤作用机理以及多轴应力下的力学性能提供参考。
For the opulence and good durability of raw material, the concrete is widely used in many types of building structures. However, as a kind of composite material, it is different from the isotropic homogeneous material, for example, steel. It reflects polymorphism, porosity and heterogeneity in mesoscopic level, and discreteness, randomness of mechanical properties in macroscopic level. All of these special performance will seriously effect the mechanical behavior and seismic capability of the structures.
     Compared with the Ordinary Concrete, the strength of cement paste in Super High Strength and High Performance Concrete (SHSHPC) is higher, almost eaqual to the strength of aggregate, which makes SHSHPC reflect higher brittleness and stronger uniformity. But in the area of mechanical properties, the randomness and discreteness of SHSHPC still cannot be avoided. According to the mechanical properties of the concrete material mentioned above, this paper do research as follows:
     Based on the uniaxial compression stochastic damage spring model which is widely used in the area of stochastic damage, the probability density function of the weibull distribution and the logarithmic normal distribution are introduced to describe the probability density of the ultimate strain of meso-element, and then a uniaxial compression stochastic damage constitutive model of meso-statistics which applied to not only the Oridinary Concrete, but also to the SHSHPC, using the fractal dimension as a representation of homogeneous degree, is established by means of comparing the two types of distribution probability density function; the damage variable is defined as a ratio of elastic modulus variation during the damage process of concrete and the initial elastic modulus on the basis of strain equivalence hypothesis, then the parameters in the model are fixed via CT scanning test and uniaxial compression experiment.
     Based on the“damage factor”put forward by Du Rongqiang, the damage evolution equation under uniaxial stress state is deduced to the axial stress state. Therefore, the statistics stochastic damage constitutive model of meso-statistics under the multi-axial stress is developed. The uniaxial and multiaxial damage constitutive model put forward in this paper can accurately reflect the damage evolution regularity of concrete by comparing them with the test results and other research results.
     Considering the need of experimental verification, three kinds of SHSHPC with different strength grade are prepared , at the same time, the mix proportion of SHSHPC is briefly introduced, the effect of water-binder ratio, the consumption of cementitious material and the coarse aggregate gradation etc on the mechanics properties of SHSHPC is analyzed; the differential box counting theory is applied to count the fractal dimension of concrete to research the relationship between the dimension of fracture surface and the parameters mentioned above on the basis of computed tomography (CT) scanning test, and then the mechanism of fractal damage of SHSHPC is reasonably explained.
     This research provides not only the theoretical basis for the application of SHSHPC, but also the knowledge to understand the mechanism of the internal components of the concrete. The research of this paper is useful on further research of the mesoscopic damage mechanism of concrete and the mechanical properties of concrete under multiaxial stress.
引文
[1-1]林皋,刘军,胡志强.混凝土损伤类本构关系研究现状与进展[J].大连理工大学学报. 2010, 50(6): 1055-1065.
    [1-2] Sidoroff F. Descrption of anisotropic damage application to elasticity[C]. IUTAM Colloquium, Physic Nononlinearities in Structural Analysis. Berlin: Springer-Verlag, 1981: 237-244.
    [1-3] Krajcinovic, Fonseka G U. Continuum damage theory of brittle materials, Part 1: General theory[J]. Journal of Applied Mechanics, 1981, 48(4): 809-824.
    [1-4] Comic C, Perego U. Fracture energy based brdissipative damage model for concrete[J]. International Journal of Solids and Structures, 2001, 38(36-7): 6427-6454.
    [1-5] YAZDANI S, SCHREYER H L. Combined plasticity and damage mechanics model for plain concrete[J]. Journal of Engineering Mechanics, 1990, 116(7): 1435-1450.
    [1-6] Lee J, Fenves G L. A plastic-damage concrete model for earthquake analysis of dams[J]. Earthquake Engineering and Stuctural Dynamics, 1998, 27(9): 937-956.
    [1-7] Faria R, Oliver J, Cervera M. A strain-based plastic viscous-damage model for massive concrete structures[J]. International Journal of Solids and Structures, 1998, 35(14): 1533-1558.
    [1-8] Simo J C, Ju J W. Strain-and stress-based continuum damage, models-Ⅰ,Ⅱ. Formulation[J]. International Journal of Solids and Structures, 1987, 23(7):821-840.
    [1-9] Ju J W. On energy-based coupled elastoplastic damage theories: constitutive modeling and computational aspects[J]. International Journal of Solids and Structures, 1989, 25(7): 803-833.
    [1-10] Abu-lebdeh T M, Voyiadji G Z. Plasticity-damage model for concrete under cyclic multiaxial loading[J]. Journal of Engineering Mechanics, 1993, 119(7): 1465-1484.
    [1-11] Salari M R, Saeb S, Willam K J, et al. A coupled elastoplastic damage model for geomaterials[J]. Computer Methods in Applied Mechanics Engineering, 2004, 193(27-29): 2625-2643.
    [1-12] Resende L. A damage mechanics constitutive theory for the inelastic behaviour of concrete[J]. Computer Methods in Applied Mechanics Engineering, 1987, 60(1): 57-93.
    [1-13]吴建营.混凝土弹塑性损伤本构模型研究Ⅰ:基本公式[J].土木工程学报,2005, 38(9): 14-20.
    [1-14]村上澄男,大野信忠.微观的空けきにょぉた有效面積減少を陽に表した多軸クリープ損傷変数[J].日本機械学会論文集(A編), 1980, 46(409): 940-946.
    [1-15]杜荣强.混凝土静动弹塑性损伤模型及在大坝分析中的应用[D].大连:大连理工大学, 2006.
    [1-16] Krajcinovic D,Manuel A G S.Statistical aspects of the continuous damage theory[J]. J Solids Structures, 1982, 18(7): 551-562.
    [1-17] Desayi P.A model to simulate the strength of concrete in compression[J]. Marerian et Constructions, 1968, 1(1): 49-56.
    [1-18] Kandarpa S,Kirkner D J,Spencer B F.Stochastic damage model for brittle materials subjected to monotonic loading[J]. Journal of Engineering Mechanics, 1996, (8): 788-795.
    [1-19]李杰,吴建营.混凝土弹塑性损伤本构模型的研究[J].土木工程学报, 2005, 38(9): 14-27.
    [1-20] Li Q B, Zhang C H, Wang G L. Dynamic damage constitutive model of concrete in uniaxial tension[J]. Engineering Fracture Mechanics, 1996, 53(3): 449-455.
    [1-21]刘军.混凝土损伤及其应用[D].大连:大连理工大学, 2004.
    [1-22]陈健云,李静,林皋.基于率性混凝土损伤模型的高拱坝地震响应分析[J].土木工程学报, 2003, 36(10): 46-50.
    [1-23] Bazant Z P, Oh B H. Microplane model for progressive of concrete and rock [J]. Journal of Engineering Mechanics, 1985, 111(4): 559-582.
    [1-24]唐春安,朱万成.混凝土损伤与断裂—数值试验[M].北京:科学出版社, 2003.
    [1-25]唐雪松,蒋持平,郑健龙.弹性损伤材料的应力-应变关系与损伤演化方程[J].长沙交通学院学报. 1999, 12(4): 8-14.
    [1-26]冯西桥.脆性材料的细观损伤理论和损伤结构的安定性分析[D].北京:清华大学, 1995.
    [1-27] Gurson A L. Continuum theory of ductile rupture by void nucleation and growth. PartⅠ. Yield criteria and flow rules for porous ductile media[J]. Journal of Engineering Materials and Technology, 1997, 99(1): 2-15.
    [1-28]黄克智,肖纪美.材料的损伤断裂机理和宏微观力学理论[M].北京:清华大学出版社, 2000.
    [1-29] Bazant Z P, Belytschoko, Chang T P. Continuum model for strain softening[J]. Journal of Structural Engineering, 1984, 110: 1666-1692.
    [1-30] Jirasek M, Rolshoven S. Comparison of integral-type nonlocal plasticity models for strain-softening materials[J]. International Journal of Engineering Science, 2003, 41(13-14): 1553-1602.
    [1-31] Peerlings R H J, De Borst R, Brekelmans W A M, et al. Radient-enhanced damage for quasi-brittle materials[J].International Journal for Numerical Methods in Engineering, 1996, 39: 3391-3403.
    [1-32] Li Z X, Mroz Z. A viscoplastic model combined damage and smeared crack for softening of concrete[J]. Acta Mechanica Solida Sinica, 1995, 16(1): 22-30.
    [2-1]周孝宽,周柱,李敦玲.分形图像学[M].北京:教育出版社,1995: 60-74.
    [2-2] Ajay K. B, Jibitesh M. On calculation of fractal dimension of images[J]. Patten Recognition Letters, 2001, 22: 631-637.
    [2-3]张怀亮,卜英勇,邱显众.球形磨粒和切削磨粒轮廓分形维数研究[J].摩擦学报, 2002, 22 (4): 304-307.
    [2-4] Majudar A, Tien C. L.Fractal characterization and simulation of rough surfaces [J]. wear, 1990, 136: 313-324.
    [2-5] He. L, Zhu. J. The fractal character of processed metal surfaces[J]. Wear. 1997, 08: 17-24.
    [2-6]李国强,邓学钧.级配骨料的分形效应[J].混凝土, 1995, (1): 3-7.
    [2-7]吴科如,张东,严安等.混凝土断裂面三维重构.建筑材科学报, 1999, 2(3):261-265.
    [2-8]董毓利,谢和平.混凝土非线性力学基础[M].北京:中国建筑工业出版社, 1997: 173-181.
    [2-9]周瑞忠.混凝土结构裂纹尖端应力场奇异性的分形力学意义[J].大连理工大学学报. 1997, (supp): 67-71.
    [2-10]周克荣,肖小松,吴晓涵.混凝土立方体抗压强度尺寸效应中的分形行为[J].福州大学学报. 1996, (supp): 63-68.
    [2-11]周克荣,肖小松,吴晓涵.混凝土轴心抗压强度尺寸效应中的分形行为[J].福州大学学报. 1996, (supp): 58-62.
    [2-12]倪玉山.混凝土细观结构断裂的分形分析.大连理工大学学报. 1997, 37(S1): 72-76.
    [2-13]朱卫华,印友法.硅灰水泥浆体中微孔表面分维及对浆体的影响[J].建筑材料学报. 1998, 1(2): 150-154.
    [2-14]康光宗,湛君毅.混凝土结构裂缝宽度尺寸效应的分形行为[J].湖南城建高等专科学校学报. 1999, (2): 1-3.
    [2-15]谢和平,鞠杨.分数维空间中的损伤力学研究初探[J].力学学报, 1999, 31(3): 2-12.
    [2-16]唐明等.压汞测孔评价混凝土材料孔隙分形特征的研究[J].沈阳建筑工程学院学报. 2001, (4): 272-275.
    [3-1]于寿文,冯西桥编著.损伤力学[M].北京,清华大学出版社, 1997.
    [3-2]李杰.混凝土随机损伤力学的初步研究[J].同济大学学报(自然科学版), 2004, 32(10): 1270-1277.
    [3-3]张明,李仲辛,苏霞.准脆性材料弹性损伤分析中的概率体元建模[J].岩石力学与工程学报, 2005, 24(23): 4282-4287.
    [3-4]李杰,吴建营.混凝土弹塑性损伤本构模型的研究[J].土木工程学报, 2005 , 38(9): 14-27.
    [3-5]刘智光,陈健云,白卫峰.基于随机损伤模型的混凝土轴拉破坏过程研究[J].岩石力学与工程学报, 2009 , 28(10) : 2048-2058.
    [3-6]朱万成.混凝土断裂的细观数值模型及其应用[D].沈阳:东北大学资源与土木工程学院, 2000.
    [3-7]张歧宣.混凝土横向变形系数的实验研究[J].混凝土及加筋混凝土, 1984.
    [3-8]白晨光,魏一鸣,朱建明.岩石材料初始缺陷的分形维数与损伤演化的关系[J].矿冶, 1996 , 5(2): 17-19.
    [3-9]温世游,胡柳青,李夕兵.节理岩体损伤的分形研究[J].江西有色金属, 2000 , 14(3): 14-16.
    [3-10]高峰,赵鹏.岩石破碎度的分形度量力学与实践, 1994 , 16(2): 16-17.
    [3-11]李志斌.非线性数学物理方程的行波解[M].北京:科学出版社, 2007.
    [3-12]同济大学应用数学系.高等数学[M].北京:高等教育出版社, 2002.
    [3-13] J.Lemaitre. Evaluation of dissipation and damage in metals submitted to dynamic loading[C]. Proceedings of ICM-1, Kyoto, 1971.
    [3-14]胡时胜,王道荣.冲击载荷下混凝土材料的动态本构关系[J].爆炸与冲击, 2002 , 22(3): 242-245.
    [3-15]鞠杨.混凝土分形损伤力学理论研究.中国矿业大学北京研究生部博士后研究报告.北京: 1997.
    [3-16]谢和平,鞠杨.分数维空间中的损伤力学研究初探[J].力学学报, 1999, 31(3): 2-12.
    [3-17] Xie H P. Fractals in rock mechanics. Rotterdam, Netherlands: A.Balkema Publisher, 1993.
    [3-18]谢和平.脆性材料中的分形损伤[J].机械强度, 1995, 17(2): 75-82.
    [3-19]谢和平,薛秀谦.分形应用中的数学基础与方法.北京:科学出版社, 1997.
    [3-20]谢和平,鞠杨,董毓利.经典损伤定义中的“弹性模量法”探讨[J].力学与实践, 1997 , 19(2): 1-5.
    [3-21]余志武,丁发兴.混凝土受压力学性能统一计算方法[J].建筑结构学报, 2003, 24(4): 41-46.
    [3-22]丁发兴,余志武,欧进萍.混凝土单轴受力损伤本构模型[J].长安大学学报(自然科学版), 2008, 28(4): 70-73.
    [3-23]曲艺.普强高性能混凝土受压应力-应变全曲线试验研究[J].海岸工程, 2008, 27(3): 53-58.
    [4-1]闰晓荣.正交各向异性损伤模型在混凝土坝抗震安全评价中的应用.大连理工大硕士学学位论文, 2005.
    [4-2] Simone A, Wells GN, Sluys L. J. From continuous to discontinuous failure in a gradient-enhanced continuum damage model. Comput. Methods Appl. Mech. Engrg. 2003, 192, 4581-4607.
    [4-3] PARK H, KIM J Y. Plasticity model using multiple failure criteria for concrete in compression [J].Int J Solids Struct, 2005, 42: 2303-232.
    [4-4]江见鲸,叶列平,陆新征.混凝土结构有限元分析[M].北京,清华大学出版社, 2004.
    [4-5]杜荣强,林皋.混凝土弹塑性多轴损伤模型及其应用[J].大连理工大学学报, 2007, 47(4): 567-572.
    [4-6] Mahnken R, Tikhomirov D, Stein E. Implicit integration scheme and its consistent linearization for an elastoplastic-damage model with application to concrete [J]. Comput Struct, 2000, 75: 135-143.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700