Abstract

Wet granular materials develop both shear stresses and normal stresses during simple shear. Over a certain range of shear rate levels, both the shear stress and the normal stress that develop are linearly proportional to the shear rate. In addition, such materials exhibit permanent increase in volume during simple shear. In this article, a model is developed to capture these features of the mechanical behavior of such wet granular materials. The model is developed within a Gibbs-potential-based thermodynamic framework utilizing the notion of the body possessing multiple natural configurations. Specific functional forms are assumed for the Gibbs potential and the rate of dissipation and the constitutive relations are obtained by the maximizing the rate of dissipation (rate of entropy production). Dilatant behavior is captured by coupling the dissipation due to volume changes to the dissipation associated with the distortion of the material.

摘要

湿颗粒材料在简单剪切过程中会产生剪切应力和法向应力。在一定范围的剪切速率水平上，产生的剪切应力和法向应力都与剪切速率成线性比例。此外，此类材料在简单剪切过程中体积会永久增加。在本文中，开发了一个模型来捕捉这种湿颗粒材料的机械行为的这些特征。该模型是在基于吉布斯势的热力学框架内开发的，利用身体具有多种自然配置的概念。Gibbs势和耗散率假设特定的函数形式，并且通过最大化耗散率（熵产生率）获得本构关系。