标题： 可逆解封的力学 显示英文标题

标题： Mechanics of Reversible Unzipping

摘要： 我们研究了在准静态端点载荷作用下，弹性层可逆脱粘（解卷）的力学行为。 在微观层面，该系统通过一个弹性粒子链来模拟，这些粒子通过可断裂的弹簧与刚性基础相互作用。 这样的系统可以视为描述从聚合物胶带剥离、细胞滚动、壁虎纤维结构的工作到DNA变性的广泛现象的典型模型。 我们构建了离散模型的严格连续极限，该极限能够捕捉稳定和亚稳态配置，并对弹性与粘附相互作用之间的相互作用进行了详细的参数研究。 我们表明，该模型能够再现实验观察到的从粘附前沿的渐进演化到宏观粘附层段的突然完全脱粘的突然转变。 随着微观参数的变化，宏观响应从准延性变为准脆性，同时粘附滞后环的尺寸相应减小。 在微观尺度上，这对应于脱粘前沿（域壁）结构从“局部”到“扩散”的转变。 我们在内部长度尺度远小于系统尺寸的极限情况下，得到了临界脱粘阈值的显式表达式。 实现的微观机制参数控制可用于设计新的仿生粘附装置和机器。 显示英文摘要

摘要： We study the mechanics of a reversible decohesion (unzipping) of an elastic layer subjected to quasi-static end-point loading. At the micro level the system is simulated by an elastic chain of particles interacting with a rigid foundation through breakable springs. Such system can be viewed as prototypical for the description of a wide range of phenomena from peeling of polymeric tapes, to rolling of cells, working of gecko's fibrillar structures and denaturation of DNA. We construct a rigorous continuum limit of the discrete model which captures both stable and metastable configurations and present a detailed parametric study of the interplay between elastic and cohesive interactions. We show that the model reproduces the experimentally observed abrupt transition from an incremental evolution of the adhesion front to a sudden complete decohesion of a macroscopic segment of the adhesion layer. As the microscopic parameters vary the macroscopic response changes from quasi-ductile to quasi-brittle, with corresponding decrease in the size of the adhesion hysteresis. At the micro-scale this corresponds to a transition from a `localized' to a `diffuse' structure of the decohesion front (domain wall). We obtain an explicit expression for the critical debonding threshold in the limit when the internal length scales are much smaller than the size of the system. The achieved parametric control of the microscopic mechanism can be used in the design of new biological inspired adhesion devices and machines.