基于CLoE与Gudehus-Bauer亚塑性模型的颗粒材料应变局部化对比研究  

A comparative analysis of strain localization of granular materials based on CLoE and Gudehus-Bauer hypoplastic models

作　　者：陈龙[1] 楚锡华[1] 张明龙[1] 徐远杰[1] 

机构地区：[1]武汉大学土木建筑工程学院,武汉430072

出　　处：《岩土力学》2013年第11期3306-3314,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.10802060;No.11172216);国家重点基础研究发展计划(No.2010CB731502)

摘　　要：基于CLoE与Gudehus-Bauer亚塑性模型数值模拟了平面应变条件下Hostun砂的应变局部化现象。从侧向压力和初始缺陷两个方面对比研究了两种模型所预测应变局部化的产生及演化模式。结果表明:(1)两种模型均能反映Hostun砂刚度随着侧向压力提高而增大的现象。(2)相比Gudehus-Bauer亚塑性模型,CLoE亚塑性模型所得出的应变局部化形态与试验结果更加一致。(3)CLoE亚塑性模型能够反映随着荷载增加,砂的体积先膨胀后缩小的特点。(4)相比Gudehus-Bauer亚塑性模型,CLoE亚塑性模型所得到的应变-应力曲线能够更明显地反映应变局部化带中单元的软化现象。(5)CLoE亚塑性模型能够更好地模拟由初始缺陷导致的不均匀应变。总的来说,所得的数值结果表明,CLoE亚塑性模型能够较好地模拟侧向压力和初始缺陷对应变局部化的影响,在模拟应变局部化现象方面较Gudehus-Bauer更有优势。然而,现有CLoE亚塑性模型无法考虑孔隙比,也未包含颗粒材料内尺度变量,有待进一步完善。To compare CLoE and Gudehus-Bauer hypoplastic models, a series of finite element analyses were carded out on modeling the strain localization for Hostun sand under plane strain condition. The strain localization was analyzed mainly in terms of different confining pressures and same initial imperfection. The results are drawn as follows. （1） Compressive hardening can be observed by two hypoplastic models; the stiffness of Hostun sand rises with the increasing of confining pressures. （2） The pattern of strain localization from the results of CLoE hypoplastic model is more compatible with the results of experiments than Gudehus-Bauer model. （3） CLoE hypoplastic model can simulate volume expansion before shrink with the increase of load of Hostun sand. （4） The softening behavior under high confining pressures of the elements in strain localization is more obvious in the strain-stress curve based on CLoE hypoplastic model. （5） CLoE hypoplastic model is better than Gudehus-Bauer model in simulating the nonuniform strain localization which is caused by initial imperfection. All in all, numerical results suggest that CLoE model performs better than Gudehus-Bauer model in modeling strain localization. What＇s more, influences of confining pressure and initial imperfection can be modeled by CLoE hypoplastic model. However, CLoE model should be improved because of void ratio and intrinsic length scales unconsidered.

关 键 词：颗粒材料 亚塑性模型 应变局部化 有限元模拟 

分 类 号：TU431[建筑科学—岩土工程]