The present work investigates nonlinear behavior in large amplitude oscillatory shear (LAOS) of unsaturated wet granular materials using pressure-imposed rheometric measurements that enable to explore how the material properties characterizing the flow response depend on both strain amplitude and frequency of deformation. Away from the quasistatic limit, we show that the energy dissipated per unit volume in a single LAOS cycle, which can be visualized by the area enclosed by the Lissajous curve of stress versus strain, is an increasing function of the viscosity of the wetting liquid and is also influenced by the reduced pressure (comparing the cohesive to confining forces) and the frequency. Introducing the inertial number $I$ and the viscous number $I_v$ as previously done, it is shown that the influence of surface tension, viscosity, and driving frequency can be captured by plotting the dissipated energy per unit volume versus the viscous number: a good collapse is obtained. It is shown that an increase in liquid content shifts the whole curve of the dissipated energy upwards, indicating that the overall dissipation mechanism does not change with liquid content, only the energy dissipation related to the internal structure and its breakdown changes.

中文翻译：

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不饱和湿颗粒物质大幅度振荡剪切中的粘性耗散

目前的工作使用施加压力的流变测量来研究不饱和湿颗粒材料的大幅度振荡剪切 (LAOS) 中的非线性行为，从而能够探索表征流动响应的材料特性如何取决于应变幅度和变形频率。远离准静态极限，我们表明在单个 LAOS 循环中每单位体积耗散的能量（可以通过应力与应变的利萨如曲线所包围的面积可视化）是润湿液体粘度的递增函数，并且也受降低的压力（比较内聚力与限制力）和频率的影响。引入惯性数$我$和粘性数${我}_v$如前所述，表明可以通过绘制每单位体积的耗散能量与粘性数的关系来捕获表面张力、粘度和驱动频率的影响：获得良好的塌陷。结果表明，液体含量的增加使整个耗散能量曲线向上移动，表明整体耗散机制不随液体含量变化，只有与内部结构及其击穿相关的能量耗散发生变化。