泥质粉砂岩统一黏塑性模型的研究

发布时间：2018-01-14 04:06

本文关键词：泥质粉砂岩统一黏塑性模型的研究　出处：《岩土力学》2016年S1期 　论文类型：期刊论文

【摘要】：统一黏塑性理论假设材料的应变仅由弹性应变和黏塑性应变组成。包含应力的黏塑性应变率表达方式,可以清晰地体现岩石材料应力增长率随应变加载速率相关的特性、在持续的偏压下的蠕变特性以及在恒定的应变下的松弛特性,但微分方程表示的本构模型在实际运用中存在计算上的困难。将无损伤Lemaitre统一黏塑性模型转换成关于应力的积分形式,并运用一致渐进展开算法得到其近似解,最后建立了基于近似解的牛顿迭代格式。开展了不同围压条件下泥质粉砂岩的三轴松弛试验,并将试验数据用于黏塑性模型的参数反分析,结果表明模型能够较好地反映泥质粉砂岩在长期作用下的力学行为特征。
[Abstract]:The unified viscoplastic theory assumes that the strain of the material is only composed of elastic strain and viscoplastic strain. The characteristics of the stress growth rate related to the strain loading rate, the creep characteristics under the continuous bias pressure and the relaxation characteristics under the constant strain can be clearly reflected. But the constitutive model expressed by differential equation is difficult to be calculated in practical application. The undamaged Lemaitre unified viscoplastic model is converted into the integral form of stress. The approximate solution is obtained by using the uniform asymptotic expansion algorithm. Finally, the Newton iteration scheme based on the approximate solution is established, and the triaxial relaxation tests of the argillaceous siltstone under different confining pressures are carried out. The experimental data are applied to the parameter back analysis of the viscoplastic model. The results show that the model can well reflect the mechanical behavior of argillaceous siltstone under the long-term action.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;山东大学岩土与结构工程研究中心;
【基金】：国家重点基础研究发展计划(973)项目(No.2015CB057906) 国家自然科学基金杰出青年基金(No.51225902),国家自然科学基金(No.51379007,No.51409245)~~
【分类号】：TU45
【正文快照】： 1 引言岩石材料在不同应变加载速率下表现出不同的应力增长速率和峰值应力,在持续的偏压下能表现出应变随时间而增长的蠕变特性,在恒定的应变控制下能表现出应力随时间而消散的松弛特性,这些现象都表明岩石材料的力学行为具有时效特性[1]。经典塑性理论以及蠕变理论都无法

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