Predicting the onset of shear band is of significance in understanding the failure of geomaterials. The prediction accuracy is dictated by the constitutive model used for the description of the pre‐bifurcation behaviour. In this study, we first modify a recently proposed hypoplastic constitutive model by incorporating a general strength criterion and a stiffness function. We proceed to consider the onset of shear band in sand under true triaxial conditions. We demonstrate that our analyses capture the pre‐bifurcation stress–strain relationship at different values of intermediate principal stress and predict fairly well the onset of shear band. The acoustic tensor criterion generally adopted in elastoplastic approaches is inadequate for hypoplastic approaches. No special non‐coaxial treatment is required for the present approach to yield a reasonable variation trend of bifurcation strain with intermediate principal stress ratio $b$.

中文翻译：

---

真三轴条件下含塑性的砂土中剪切带的分叉分析

预测剪切带的开始对于理解土工材料的破坏具有重要意义。预测精度由用于描述分叉前行为的本构模型决定。在这项研究中，我们首先通过合并一般强度标准和刚度函数来修改最近提出的塑性本构模型。我们继续考虑在真正的三轴条件下砂土中剪切带的出现。我们证明了我们的分析在不同的中间主应力值下捕获了分叉前的应力-应变关系，并且很好地预测了剪切带的出现。弹塑性方法中通常采用的声张量准则不足以用于塑性变形方法。$b$。