Abstract Cosserat continuum model has attracted increasing interest for describing the mechanical behavior of microstructured solids. Existing formulation of Cosserat continuum model often overlooks chiral effects that arise from coupling between stretching deformations and the micro-rotation. Here, we introduce an extended Cosserat model that accounts for such a coupling. We discover the links of the extended model to the mechanics of granular materials and identify the continuum and grain-scale parameters that are the source of postulated chirality. The micro-rotation is shown to be related to the coupling of shear and normal responses of grain-pair interactions. The consequences of this chirality are then explicated with the aid of numerical examples. Through parametric studies we also demonstrate the possibility of measuring the effects of this type of chirality in experiments.

中文翻译：

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2D Cosserat 介质中的手性与拉伸-微旋转耦合相关，链接到颗粒微力学

摘要 Cosserat 连续介质模型在描述微结构固体的力学行为方面引起了越来越多的兴趣。Cosserat 连续介质模型的现有公式常常忽略由拉伸变形和微旋转之间的耦合引起的手性效应。在这里，我们引入了一个扩展的 Cosserat 模型来解释这种耦合。我们发现了扩展模型与颗粒材料力学的联系，并确定了作为假定手性来源的连续介质和颗粒尺度参数。微旋转被证明与颗粒对相互作用的剪切和正常响应的耦合有关。然后借助数值例子解释这种手性的后果。