Abstract The characteristics and mechanisms of stress fluctuation are not fully understood, especially for the large fluctuation at the cylinder/hopper transition. In this paper, we performed wall normal stress tests in a laboratory-scale silo which consisted of the cylinder section and hopper section. The amplitude and period characteristics of wall normal stress fluctuation at the top of the hopper were investigated. The result shows that the peak of the stress fluctuation and the maximum of the fluctuation range at the hopper top can reach 1.60 times and 0.64 times of the theoretical value, respectively. The amplitude of the stress fluctuation at the hopper top is independent of the outlet diameter, while the period of the stress fluctuation decreases with the increase of the outlet diameter. Furthermore, the stress-state transition and the shear zones in bulk solids are reasonably responsible for the periodic stress fluctuation at the hopper top.

中文翻译：

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筒仓卸料过程中壁面法向应力动态特性试验研究

摘要 应力波动的特征和机制尚不完全清楚，尤其是在筒体/料斗过渡处的大波动。在本文中，我们在实验室规模的筒仓中进行了壁面法向应力测试，筒仓由筒体部分和料斗部分组成。研究了料斗顶部壁面法向应力波动的幅值和周期特性。结果表明，料斗顶部应力波动峰值和波动幅度最大值分别达到理论值的1.60倍和0.64倍。料斗顶部应力波动幅度与出口直径无关，而应力波动周期随着出口直径的增加而减小。此外，