Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2019 Oct 18;123(16):168002. doi: 10.1103/PhysRevLett.123.168002.
Inserting a rigid object into a soft elastic tube produces conformal contact between the two, resulting in contact lines. The curvature of the tube walls near these contact lines is often large and is typically regularized by the finite bending rigidity of the tube. Here, it is demonstrated using experiments and a Föppl-von Kármán-like theory that a second, independent, mechanism of curvature regularization occurs when the tube is axially stretched. In contrast with the effects of finite bending rigidity, the radius of curvature obtained increases with the applied stretching force and decreases with sheet thickness. The dependence of the curvature on a suitably rescaled stretching force is found to be universal, independent of the shape of the intruder, and results from an interplay between the longitudinal stresses due to the applied stretch and hoop stresses characteristic of curved geometry. These results suggest that curvature measurements can be used to infer the mechanical properties of stretched tubular structures.
将刚性物体插入柔软的弹性管中会在两者之间产生保形接触，从而形成接触线。这些接触线附近的管壁曲率通常很大，并且通常通过管的有限弯曲刚度来正则化。在这里，通过实验和类似于 Föppl-von Kármán 的理论证明，当管被轴向拉伸时，会出现第二种独立的曲率正则化机制。与有限弯曲刚度的影响相反，所获得的曲率半径随施加的拉伸力增大而增大，随片材厚度减小而减小。发现曲率对适当缩放的拉伸力的依赖性是普遍的，与侵入物的形状无关，并且是由由于拉伸引起的纵向应力和弯曲几何特征的环向应力之间的相互作用引起的。这些结果表明，可以使用曲率测量来推断拉伸管状结构的机械性能。
