A Thermodynamic Model for Rate-Dependent Geomaterials
A Thermodynamic Model for Rate-Dependent Geomaterials
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DOI：
10.1007/978-3-319-52773-4_56
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
Hao Wang;Xiaohui Cheng
中科院分区：
文献类型：
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作者：
Hao Wang;Xiaohui Cheng
岩土材料表现出复杂的率相关行为。深入理解和解释这些率相关行为具有重要的理论和实践价值。本文从率相关本构模型的发展出发，深入研究了土的率相关物理机制和数学模型。传统的弹粘塑性模型是在经典弹塑性模型的基础上，采用类似于流体力学中的粘性耗散来描述率相关耗散。传统的热力学模型是速率无关的。从非平衡态热力学理论出发，通过引入迁移系数矩阵，建立了一个既能反映粘性耗散又能反映非粘性耗散的速率相关的土的热力学模型。探讨了岩土力学研究者不熟悉的非粘性耗散能在多大程度上描述土的率相关特性，并对土的一维压缩和三维剪切特性进行了本构建模。模拟结果与弹粘塑性模型和实验结果进行了比较。
Geomaterials exhibit complicated rate-dependent behaviors. A deeper understanding and interpretation of these rate-dependent behaviors possess important theoretical and practical values. From the development of the rate-dependent constitutive model point of view, the paper deeply investigates the rate-dependent physical mechanisms and the mathematical models of soils. Based on the classical elasto-plastic models, traditional elasto-viscoplastic models apply viscous dissipations, similar to what has been used in fluid mechanics, for the description of rate-dependent dissipations. Traditional thermodynamic models are rate-independent. Starting from the theory of non-equilibrium thermodynamics and by introducing the matrix of migration coefficients, a thermodynamic rate-dependent model for soil is established, which is able to represent both the viscous dissipations and the non-viscous dissipations concerning rate dependency. The paper explores to which degree non-viscous dissipation, which is not familiar for the researchers of rock and soil mechanics, is able to describe the rate-dependent behaviors of soil, and carries out the constitutive modeling of one-dimensional compressional and three-dimensional shear behaviors of soil. The simulations are compared with those using elasto-viscoplastic models and the experimental results.