Abstract A new macroscopic yield criterion is derived in the present work to describe the elastoplastic mechanical behavior of composite with a porous matrix-inclusion microstructure. The influences of porosity at the microscopic scale and the bigger inclusions at the mesoscopic scale are explicitly taken into account by this criterion. The solid phase at the microscopic scale obeys to a Drucker-Prager criterion for the dilatant effect. The exact solution can be retrieved in the special case of a porous medium having a Drucker-Prager type matrix. This improves fundamentally the one proposed in Shen et al. (2013) . This criterion is applied to describe the peak stresses of Callovo Oxfordian argillite obtained by the uniaxial and triaxial compression tests with different compositions and different confining pressures. Then, a complete constitutive model is established with a plastic hardening behavior and the non-associated plastic flow rule. The evolutions of the microstructure, such as the variations of the porosity and the volume fraction of inclusions with the loading process, can be fully considered by this micromechanics based model. By comparing the numerical results with the experimental data, the proposed model is able to capture the main features of the studied geomaterial with a porous matrix-inclusion microstructure.

中文翻译：

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具有多孔基体-包裹体微结构的地质材料多尺度弹塑性本构模型

摘要 在目前的工作中推导出一个新的宏观屈服准则来描述具有多孔基体-夹杂物微观结构的复合材料的弹塑性力学行为。该标准明确考虑了微观尺度的孔隙度和细观尺度的较大夹杂物的影响。微观尺度上的固相服从膨胀效应的 Drucker-Prager 准则。在具有 Drucker-Prager 型矩阵的多孔介质的特殊情况下，可以得到精确解。这从根本上改进了 Shen 等人提出的方法。(2013)。该准则用于描述不同成分和不同围压条件下通过单轴和三轴压缩试验获得的 Callovo Oxfordian 泥质岩的峰值应力。然后，建立了具有塑性硬化行为和非关联塑性流动规则的完整本构模型。这种基于微观力学的模型可以充分考虑微观结构的演变，例如孔隙率和夹杂物体积分数随加载过程的变化。通过将数值结果与实验数据进行比较，所提出的模型能够捕捉具有多孔基质-包裹体微观结构的研究地质材料的主要特征。