Granular micromechanics model for damage and plasticity of cementitious materials based upon thermomechanics*
Granular micromechanics model for damage and plasticity of cementitious materials based upon thermomechanics*
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DOI：
10.1177/1081286515576821
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发表时间：
2020-10-01
影响因子：
2.6
通讯作者：
Poorsolhjouy, Payam
中科院分区：
文献类型：
--
作者：
Misra, Anil;Poorsolhjouy, Payam
单块胶凝材料的力学性能受到其颗粒特性的显著影响。本文描述了一种基于颗粒微观力学范式和热力学的考虑胶凝材料粒度影响的方法。因此，宏观尺度的本构方程，利用晶粒尺度的力-位移关系已被推导出来。在这个推导中，晶粒尺度的自由能和耗散和宏观尺度行为之间的联系建立在热力学框架的基础上。用颗粒对相互作用自由能的形式给出了柯西应力张量的表达式。此外，利用自由能和耗散势，得到了一个颗粒尺度的Clausius-Duhem型不等式。因此，颗粒间本构方程得到的通常方式与例外，这些是基于简单的物理动机的自由能和耗散函数制定的颗粒对相互作用。推导出的模型是用来模拟各种各样的实验测试，已在文献中报道，以评估多轴条件下的材料响应。分析结果的目的是揭示晶粒尺度机制和宏观尺度行为之间的联系。
The mechanical behavior of monolithic cementitious materials is known to be significantly affected by their granular nature. This paper describes an approach to incorporate the effects of granularity for cementitious material based upon the granular micromechanics paradigm and thermomechanics. As a result, macro-scale constitutive equations that utilize grain-scale force-displacement relationships have been derived. In this derivation, the connections between grain-scale free energy and dissipation and the macro-scale behavior are established based upon the thermomechanics framework. Expression for Cauchy stress tensor is obtained in terms of the free energy of grain-pair interactions. In addition, the free energy and dissipation potential of grain-pair interactions are used to find a grain-scale Clausius-Duhem type inequality. Thus, inter-granular constitutive equations are obtained in the usual manner with the exception that these are based upon simple physically motivated free energy and dissipation functions formulated in terms of grain-pair interactions. The derived model is used to simulate a wide variety of experimental tests that have been reported in the literature to evaluate material response under multi-axial conditions. The results are analyzed with the aim to reveal the connections between grain-scale mechanisms and the macro-scale behavior.