This article studies the fundamental problem of separating two adhesive elastic fibers based on numerical simulation employing a recently developed finite element model for molecular interactions between curved slender fibers. Specifically, it covers the two-sided peeling and pull-off process starting from fibers contacting along its entire length to fully separated fibers including all intermediate configurations and the well-known physical instability of snapping into contact and snapping free. We analyze the resulting force-displacement curve showing a rich and highly nonlinear system behavior arising from the interplay of adhesion, mechanical contact interaction and structural resistance against (axial, shear and bending) deformation. While similar to one-sided peeling studies from the literature, a distinct initiation and peeling phase can be observed, the two-sided peeling setup considered in the present work reveals the extended final pull-off stage as third characteristic phase. Moreover, the influence of different material and interaction parameters such as Young's modulus as well as type (electrostatic or van der Waals) and strength of adhesion is critically studied. Most importantly, it is found that the maximum force occurs in the pull-off phase for electrostatic attraction, but in the initiation phase for van der Waals adhesion. In addition to the physical system behavior, the most important numerical aspects required to simulate this challenging computational problem in a robust and accurate manner are discussed. Thus, besides the insights gained into the considered two-fiber system, this study provides a proof of concept facilitating the application of the employed model to larger and increasingly complex systems of slender fibers.

中文翻译：

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通过新的计算梁相互作用模型研究粘性弹性纤维的剥离和拉断行为

本文基于数值模拟研究了分离两种粘性弹性纤维的基本问题，采用了最近开发的有限元模型，用于弯曲细长纤维之间的分子相互作用。具体而言，它涵盖了从沿其整个长度接触的纤维到完全分离的纤维（包括所有中间结构）以及众所周知的咬合接触和自由咬合的物理不稳定性的双面剥离和拉脱过程。我们分析了由此产生的力-位移曲线，显示了由于粘附、机械接触相互作用和结构抵抗（轴向、剪切和弯曲）变形的相互作用而产生的丰富且高度非线性的系统行为。虽然类似于文献中的片面剥离研究，可以观察到明显的起始和剥离阶段，本工作中考虑的两侧剥离设置揭示了延长的最终剥离阶段作为第三个特征阶段。此外，还严格研究了不同材料和相互作用参数（例如杨氏模量以及类型（静电或范德华）和粘合强度）的影响。最重要的是，发现最大力出现在静电吸引的拉离阶段，但出现在范德华粘附的引发阶段。除了物理系统行为之外，还讨论了以稳健和准确的方式模拟这一具有挑战性的计算问题所需的最重要的数值方面。因此，除了对所考虑的双纤维系统的见解之外，