Jayawardana Wathsala M A, Liao Yangchao, Li Zhaofan, Xia Wenjie, Croll Andrew B
Department of Physics, North Dakota State University, Fargo, USA.
Department of Civil, Construction and Environmental Engineering, North Dakota State University, Fargo, ND, USA.
Soft Matter. 2023 Feb 8;19(6):1081-1091. doi: 10.1039/d2sm01584f.
When a thin sheet is confined to a volume much smaller than its length (or width), it forms a complex state of sharp bends, point-like developable cones (d-cones) and extended ridges known as crumpled matter. One interesting feature of this state, is its high resistance to compression given its light weight. While the origins of this strength still remain a matter of debate, much has been learned through simple experiments and models. Very little work has explored how crumpling is affected by the sheet's topology, which is curious given the close relation between geometry and mechanics. In this work, we couple confocal microscopy with simple force experiments and coarse-grained molecular dynamics (CG-MD) simulations to explore how adding cuts to a sheet alters its behavior in the crumpled state. We find that cutting does not significantly alter the overall compressive behaviour: force scales as a power law irrespective of cuts and magnitudes are only slightly reduced by cutting. Remarkably, when examining regions of high curvature in the crumpled sheets we see evidence of significant changes in the distribution of curvature in cut sheets.
当一张薄片被限制在一个比其长度(或宽度)小得多的体积中时,它会形成一种由尖锐弯曲、点状可展圆锥体(d - 圆锥体)和延伸脊组成的复杂状态,即所谓的皱缩物质。这种状态的一个有趣特征是,尽管重量轻,但它对压缩具有很高的抵抗力。虽然这种强度的起源仍存在争议,但通过简单的实验和模型已经有了很多了解。鉴于几何形状和力学之间的密切关系,很少有研究探讨薄片的拓扑结构如何影响皱缩过程。在这项工作中,我们将共聚焦显微镜与简单的力实验以及粗粒度分子动力学(CG - MD)模拟相结合,以探究在薄片上添加切口如何改变其在皱缩状态下的行为。我们发现,切割并不会显著改变整体的压缩行为:力随幂律变化,与切口无关,并且仅通过切割会使力的大小略有降低。值得注意的是,当检查皱缩薄片中的高曲率区域时,我们发现有证据表明切割后的薄片中曲率分布发生了显著变化。