摘要
根据复杂加载条件下饱和砂土排水平面应变压缩试验,分析了砂土的速率相关的黏性特性.试验发现砂土存在显著的加载速率效应、蠕变变形和应力松弛,并且在应变速率突变、蠕变或应力松弛之后,以新的应变速率重新加载时呈现出高刚度行为.针对砂土的变形强度特性提出了一种非线性有限元计算方法,砂土本构关系采用了三要素弹黏塑性本构模型.将有限元计算结果与试验结果进行比较,表明建议的有限元计算方法不仅可以较为精确地模拟砂土的平均应力-应变关系,同时也可以模拟包含变应变速率加载、蠕变加载、应力松弛加载的全过程黏塑特性.
Based on the experimental results from drained plane strain compression（PSC）tests on saturated sand under complex loading histories,the rate-dependent behaviors of sand due to its viscous properties were studied.It was found that sand exhibits obvious loading rate effects,creep deformation and stress relaxation.When monotonic loading was restarted immediately after a step-change in the strain rate or following a creep loading or stress relaxation stage,the stress-strain relation showed a very high tangent stiffness.A nonlinear finite element method（FEM）analysis technique was developed.In the FEM analyses,the sand was described by the three-component elasto-viscoplastic constitutive model.It was shown that the present FEM analyses can properly simulate the global stress-strain relationships obtained from the experiments.And the whole process including the variable strain rate loadings,the creep loading and stress relaxation stages were implemented in the FEM analyses.
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第1期13-17,47,共6页
Journal of Tongji University:Natural Science
基金
国家自然科学基金(50679056
40972176)
教育部新世纪优秀人才支持计划(NCET-06-0378)
上海市曙光计划(05SG25)
上海市重点学科建设项目(B308)
关键词
砂土
弹黏塑性
加载速率
有限元
蠕变
sand
elasto-viscoplastic properties
loading rate
finite element method
creep
