The current study investigates the non-coaxial plastic flow in granular media where the principal directions of incremental plastic strain differ from those of the current stress (and of the current fabric tensor). The stress probing technique is used with Discrete Element Method simulations to capture the plastic response of a 2D granular assembly to loading increments along different directions in stress space, including non-coaxial ones. A general form for the plastic flow is suggested, based on multi-mechanism plasticity theory which is demonstrated to be capable of capturing the essential characteristics of the non-coaxial plastic flow. Deviations between DEM results and model predictions are associated with the incrementally nonlinear nature of the response. The analysis of the results indicate that, at a given stress state, the plastic yielding direction is not coaxial with the current stress. The significance of the non-coaxial plastic flow is shown to be around $20\%$ for lower deviatoric stresses, but this value diminishes as the peak stress is achieved, hinting to the dominance of a single mechanism at failure. The study concludes by comparing the developed model with two well-known non-coaxial models in the literature, where the performance of the developed model is found to be close to the double-shearing theory.

当前的研究调查了颗粒介质中的非同轴塑性流动，其中增量塑性应变的主要方向不同于当前应力（和当前织物张量）的方向。应力探测技术与离散元素方法仿真一起使用，以捕获2D颗粒装配对沿应力空间中不同方向（包括非同轴方向）的载荷增量的塑性响应。根据多机理可塑性理论，提出了塑性流的一般形式，该理论被证明能够捕获非同轴塑性流的基本特征。DEM结果与模型预测之间的偏差与响应的增量非线性特性相关。结果分析表明，在给定的应力状态下，塑性屈服方向与当前应力不同轴。非同轴塑性流动的重要性被证明是围绕$20％$对于较低的偏应力，该值随着达到峰值应力而减小，这暗示了单一机制在失效时的优势。通过将开发的模型与文献中的两个著名的非同轴模型进行比较，得出结论，在该文献中，开发的模型的性能接近双剪切理论。