高召宁.颗粒物质的分形特征与其物理力学性质的关系探讨[J].实验力学,2011,26(3):285~290 |
颗粒物质的分形特征与其物理力学性质的关系探讨 |
Discussion of Relationship between Fractal Feature and Its Physical Mechanics Characters of Grain Matter |
投稿时间:2010-07-27 修订日期:2010-12-16 |
DOI: |
中文关键词: 非均匀性 颗粒流 分维数 敏感性 鲁棒性 |
英文关键词:non-uniformity granular flow fractal dimension sensitivity robustness |
基金项目:国家重点基础研究发展计划(973计划)(2008CB425802) |
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中文摘要: |
从颗粒流的一般本构方程出发,利用室内大型相对密度仪和直接剪切仪,针对粒径分形分布对孔隙率和内摩擦角的影响进行了实验研究。结果表明,在相同实体密度、弹性恢复系数和几何平均中值粒径条件下,随粒径分维数的增大,孔隙率增大,而内摩擦角、颗粒浓度、剪切应力系数与正应力系数均减小。进而分析了粒径分形特性对颗粒流动行为的影响,得出粒径分维数小的颗粒系统剪切应力大,系统的流动性能差,鲁棒性强;反之,分维数大的颗粒系统剪切应力小,系统的流动性能好,敏感性强。对系统组构的分形特征影响系统颗粒物质崩塌流动行为的机制进行了初步探索,为颗粒流系统的研究提供了新思路。 |
英文摘要: |
According to general constitutive equation of granular flow, the impact of size fractal distribution on porosity and internal friction angle was studied experimentally by using large-scale indoor relative densitometer and direct shear apparatus. Results show that under conditions of same physical density, same elastic recovery coefficient and same geometric mean median granular size, the porosity increases along with the fractal dimension increasing, meanwhile, the internal friction angle, particle concentration, shear stress and normal stress coefficients declines. Further more, in term of analysis of impact of size fractal distribution on flow behavior of granular flow system, it is found that as for the system with smaller fractal dimension, the shear stress is larger,the fluid is poor and the robustness is strong; On the contrary, as for the system with larger fractal dimension, the shear stress is smaller,the fluid is good and sensitivity is strong. The discussion of impact mechanism of fractal characteristic on collapse flow behavior of granular material may offer a new idea for the study of granular flow system. |
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