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The yield surface of granular matarials determined by the fabric in three-dimensional stresses

颗粒材料的屈服面由织物在三维应力下决定

基本信息

批准号：
09650548
负责人：
MATSUOKA Hajime
金额：
$ 2.05万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650548/
关键词：
Yield surface Fabric yield criterion Constitutive Equation Stress history General stress Elastoplasic model Granular material 3次元粒子接点角分布

项目摘要

1) The yield surface of granular materials determined by the fabricAlmost all yield surface of granular materials have been determined phenomenologically by the experimental results. In this study, however, the yield surface of granular materials is proposed on the basis of the microscopic fabric which is evaluated by the distribution of interparticle contact normal It is expressed in (siguma_y, siguma_x and tau_y) space in the case of two dimensional stress state and in general stress space in the case of three dimensional stress state. The proposed method can easily explain the yield due to the pure rotation of the principal stress axis with the values of the principal stresses unchanged.2) Generation of elastoplastic model for granular materialsA transformed stress tensor has been proposed by comparing the shapes of the Extended Mises criterion and the SMP criterion in principal stress space. The SMP curve in the pi-plane of siguma_i is a circle and the SMP surface in the transformed principal stress space is a cone. The transformed stress tensor siguma_<ij> is applied to the Cam-clay models and the Sekiguchi-Ohta model to combine the critical state theory with the SMP criterion. The revised models, with the same soil parameters as the Cam-day models and Sekiguchi-Ohta model, are capable of predicting the drained and undrained behavior of clay in general stress conditions. Therefore, it is possible to extend any other elastoplastic models for soils, whose validity has been verified only in triaxial compression condition, to the general stress conditions by using the transformed stress tensor siguma_<ij> instead of the ordinary stress tensor siguma_<ij>. Moreover, the revised model is extended to be a unified elastoplastic model for clay and sand by introducing a new hardening parameter H, which can describe the negative and positive dilatancy characteristics of soils with the initially stress-induced anisotropy including the initial isotropy.

1)由织物确定的颗粒材料屈服面几乎所有的颗粒材料屈服面都已由实验结果唯象地确定。本文提出的颗粒材料屈服面是以颗粒间接触法向分布表征的细观组构为基础的，在二维应力状态下用（siguma_y，siguma_x和tau_y）空间表示，在三维应力状态下用一般应力空间表示。该方法可以很容易地解释由于主应力轴的纯旋转而产生的屈服，而主应力值不变。2）颗粒材料弹塑性模型的生成通过比较扩展Mises准则和SMP准则在主应力空间中的形状，提出了一种变换应力张量。在siguma_i的π平面内的SMP曲线是圆形的，而在变换的主应力空间内的SMP曲面是圆锥形的。将变换应力张量siguma_<ij>应用于剑桥模型和关口太田模型，使联合收割机理论与SMP准则相结合。修正后的模型与Cam-day模型和Sekiguchi-Ohta模型的土体参数相同，能够预测一般应力条件下粘性土的排水和不排水特性。因此，可以用变换应力张量siguma_代替通常的应力张量siguma_，将仅在三轴压缩条件下验证了其有效性的任何其它土的弹塑性模型推广到一般应力条件<ij>下<ij>。此外，通过引入新的硬化参数H，将修正模型扩展为统一的砂土和粘土弹塑性模型，该模型可以描述具有初始各向异性（包括初始各向同性）的土体的正负向异性特性。