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arXiv 2602.05669cond-mat.soft
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边界合规性选择剪切增稠悬浮液的异质动力学

Boundary compliance selects heterogeneous dynamics in shear-thickening suspensions

Changsha University of Science and Technology(长沙理工大学);Xi'an Jiaotong University(西安交通大学);Kyushu University(九州大学)

Li-Xin Shi, Meng-Fei Hu, Song-Chuan Zhao

AI总结:

研究发现边界合规性影响剪切增稠悬浮液的流动行为,通过调节油粘度控制边界合规性,揭示了异质结构的寿命和形态选择机制,为理解剪切增稠、剪切阻塞和约束力学间的相互作用提供新见解。

摘要:

约束边界机械性能可以根本改变剪切增稠悬浮液的流动行为。我们研究了一种密集的玉米淀粉悬浮液在粘性硅油层下方受剪切时的行为,利用油的粘度来调节边界合规性。流体可视化和流变学测试揭示了两种不同的流动模式。在合规性边界下,通过密度波或持久簇形成长寿命的异质性,由界面变形与颗粒重新排列之间的平衡维持。在更刚性的约束下,我们观察到短暂的阻塞事件,表现为负载承载结构在悬浮液厚度上的突然跨越以及二次应力波的出现。这些事件的起始应力在DST阈值下保持不变,与边界粘度无关。我们的结果表明,边界合规性选择异质结构的寿命和形态,为放大原本短暂的微观过程提供了途径,并为理解剪切增稠、剪切阻塞和约束力学间的相互作用提供了新的见解。

英文摘要:

The mechanical properties of confining boundaries can fundamentally alter the flow behaviour of shear-thickening suspensions. We study a dense cornstarch suspension sheared beneath a viscous silicone-oil layer, using the oil viscosity to tune boundary compliance. Flow visualisation and rheometry reveal two distinct regimes. With compliant boundaries, long-lived heterogeneities emerge via density waves or persistent clusters, maintained by a balance between interface deformation and particle rearrangement. With more resistant confinement, we observe transient jamming events, marked by abrupt spanning of load-bearing structures across the suspension thickness and the emergence of secondary stress waves. The onset stress of these events remains constant at the DST threshold, independent of bounding viscosity. Our results reveal that boundary compliance selects the lifetime and morphology of heterogeneous structures, offering a means to amplify otherwise short-lived microscopic processes and providing new insight into the interplay between shear thickening, shear jamming, and confinement mechanics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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