FE-studies on the influence of initial void ratio, pressure level and mean grain diameter on shear localization
FE-studies on the influence of initial void ratio, pressure level and mean grain diameter on shear localization
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DOI：
10.1002/(sici)1096-9853(19991225)23:15
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发表时间：
1999-12
影响因子：
4
通讯作者：
J. Tejchman;I. Herle;J. Wehr
中科院分区：
文献类型：
--
作者：
J. Tejchman;I. Herle;J. Wehr
本文关注的是在平面应变压缩试验中颗粒材料内部以自发剪切带形式出现的剪切局部化现象。研究了初始孔隙比、压力和平均粒径对剪切带厚度的影响。采用有限元方法对干砂的平面应变压缩试验进行了数值模拟，考虑了在极性（科塞尔）连续介质中建立的极性亚塑性本构关系。该关系是通过根据古德胡斯和鲍尔的非极性亚塑性本构定律用极性量（转动、曲率、偶应力和特征长度）进行扩展而得到的。它能够再现剪切局部化过程中颗粒体的基本特征。材料常数易于校准。有限元计算表明，剪切带厚度随初始孔隙比、压力水平和平均粒径的增加而增加。由颗粒转动和偶应力的出现所体现的极性效应仅在剪切带中显著。数值计算与实验结果之间的比较显示出令人满意的一致性。版权所有©1999约翰威立父子有限公司
The paper is concerned with shear localization in the form of a spontaneous shear zone inside a granular material during a plane strain compression test. The influence of an initial void ratio, pressure and a mean grain diameter on the thickness of a shear zone is investigated. A plane strain compression test with dry sand is numerically modelled with a finite element method taking into account a polar hypoplastic constitutive relation which was laid down within a polar (Cosserat) continuum. The relation was obtained through an extension of a non-polar hypoplastic constitutive law according to Gudehus and Bauer by polar quantities: rotations, curvatures, couple stresses and a characteristic length. It can reproduce the essential features of granular bodies during shear localization. The material constants can be easily calibrated. The FE-calculations demonstrate an increase in the thickness of the shear zone with increasing initial void ratio, pressure level and mean grain diameter. Polar effects manifested by the appearance of grain rotations and couple stresses are only significant in the shear zone. A comparison between numerical calculations and experimental results shows a satisfying agreement. Copyright © 1999 John Wiley & Sons, Ltd.