We perform numerical simulations of plane strain compression tests of Ottawa sand samples inspired by previous micro computed tomography experiments. The numerical code used for computations makes it possible to mimic in a realistic way the complex boundary conditions of the experimental test, and to introduce grains with complex morphologies based on Fourier descriptors measured on real sand grains. Since the introduction of a realistic roughness of the sand grains is very costly in terms of computation, we wish to determine if this roughness could be replaced by an artificial increase of the contact friction coefficient, without modifying the mechanical response of the sample and the localization patterns. Numerical results show that such a smoothing is actually possible to a certain extent, and guidelines are provided in order to choose with care the amount of roughness that can be compensated by friction. The resulting reduction of the computation time makes it possible to foresee future large scale simulations of realistic granular samples.

中文翻译：

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摩擦可以代替颗粒材料数值模拟中的粗糙度吗？

我们对渥太华砂样品的平面应变压缩试验进行了数值模拟，受到以前的微计算机断层摄影实验的启发。用于计算的数字代码可以以现实的方式模拟实验测试的复杂边界条件，并可以基于在真实沙粒上测量的傅立叶描述符引入具有复杂形态的晶粒。由于引入实际的砂粒粗糙度在计算方面非常昂贵，因此我们希望确定是否可以通过人为增加接触摩擦系数来代替使用这种粗糙度，而无需改变样品的机械响应和定位模式。数值结果表明，这种平滑实际上在一定程度上是可能的，提供了一些指导原则，以便谨慎选择可通过摩擦补偿的粗糙度。由此减少的计算时间使得可以预见未来的真实颗粒样本的大规模模拟。