基于梯度塑性理论的岩样峰后变形特征研究*

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Abstract Analytical solutions of axial，lateral，circumferential and volumetric strains，and post-peak Poissons ratio of rock specimen subjected to shear failure in uniaxial compression are proposed. Hookes law is adopted to describe elastic strain. Plastic strain is determined by gradient-dependent plasticity where internal length controls the thickness of shear band. Axial stress-axial strain curve，axial stress-lateral strain curve，axial stress-volumetric strain curve and axial strain-volumetric strain curve exhibit bi-linear behaviors due to the fact that constitutive relations of linear elasticity and linear softening are utilized. However，in the strain-softening stage，the curve of axial stress and post-peak Poissons ratio is nonlinear. Different from the Poissons ratio prior to the onset of shear strain localization，the post-peak Poissons ratio changes with axial stress levels and is possibly greater than 0.5. The volumetric strain measured in experiments or calculated by the present theoretical analysis depends on axial and lateral strains，which is related to the geometrical dimensions of rock specimens. Therefore，the slope of the axial stress-volumetric strain curve in strain-softening stage cannot be taken as a constitutive parameter，which is different from that of the axial stress-pure volumetric strain curve. The pure volumetric strain is the sum of elastic volumetric strain and plastic volumetric strain that is assumed to be due to shear dilatancy in shear band. The advantage of the present mechanical model is that the whole characteristics of deformations including post-peak Poisson’s ratio，axial，lateral，circumferential and volumetric strains can be described analytically by it.

Key words： rock mechanics strain localization post-peak deformation gradient-dependent plasticity axial strain lateral strain volumetric strain post-peak Poissons ratio

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Cite this article:

Wang Xuebin. CHARACTERISTICS OF POST-PEAK DEFORMATIONS OF ROCK IN UNIAXIAL COMPRESSION BASED ON GRADIENT-DEPENDENT PLASTICITY[J]. , 2004, 23(S1): 4292-4295.

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https://rockmech.whrsm.ac.cn/EN/Y2004/V23/IS1/4292

1 Lee J S，Pande G N. Application of a homogenization techique to one-dimensional bar exhibiting strain-softening behavior[J]. Materials and Structures，1997，30(4)：506～510

2 de Borst R，Muhlhaus H B. Gradient-dependent plasticity：formulation and algorithmic aspects[J]. International Journal for Numerical Methods in Engineering，1992，35(4)：521～539

3 Schreyer H L，Chen Z. One-dimensional softening with localization[J]. Journal of Applied Mechanics，ASCM，1986，53(6)：791～797

4 Schreyer H L. Analytical solutions for nonlinear strain-gradient softening and localization[J]. Journal of Applied Mechanics，ASCM，1990，57(4)：522～528

5 Alessandro P F，Daniele F，Ivo I. Mechanical model for failure of compressed concrete in reinforced concrete beams[J]. Journal of Structural Engineering，ASCE，2001，128(5)：637～645

6 Pan Y S，Wang X B，Li Z H. Analysis of the strain softening size effect for rock specimens based on shear strain gradient plasticity theory[J]. International Journal of Rock Mechanics and Mining Sciences，2002，39(6)： 801～805

7 王学滨，潘一山，宋维源. 岩石试件尺寸效应的塑性剪切应变梯度模型[J]. 岩土工程学报，2001，23(6)：711～714

8 王学滨，潘一山，杨小彬. 准脆性材料试件应变软化尺度效应理论研究[J]. 岩石力学与工程学报，2003，22(3)：188～191

9 Wang X B，Pan Y S. Effect of relative stress on post-peak uniaxial compression fracture energy of concrete[J]. Journal of Wuhan University of Technology-Materials Science Edition，2003，18(4)：89～92

10 Wang X B，Yang X B，Zhang Z H，et al. Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion[J]. Journal of University of Science and Technology Beijing，2004，11(1)：5～9

11 Wang X B，Yang M，Yu H J，et al. Localized shear deformation during shear band propagation in Titanium considering interactions among microstructures[J]. Trans. Nonferrous Met. Soc. China，2004，14(2)：335～339

12 Wang X B，Dai S H，Hai L，et al. Analysis of localized shear deformation of ductile metal based on gradient-dependent plasticity[J]. Trans. Nonferrous Met. Soc. China，2003，13(6)：1 348～1 353

13 王学滨，马剑，刘杰等. 基于梯度塑性本构理论的岩样侧向变形分析(I)：基本理论及本构参数对侧向变形的影响[J]. 岩土力学，2004，25(6)：904～908

14 王学滨，潘一山. 基于梯度塑性理论的岩样单轴压缩扩容分析[J]. 岩石力学与工程学报，2003，23(5)：721～724