具有接触缺陷的仿生纤维阵列的粘附强度
Adhesive strength of bio-inspired fibrillar arrays in the presence of contact defects
AI总结：
研究了单个圆形缺陷的大小和位置对仿生纤维粘合剂粘附力与系统有效合规性关系的影响，发现边缘缺陷比中心缺陷更破坏，但中心缺陷改变了脱附力学，使粘附强度对系统合规性更不敏感。
摘要：
生物启发的纤维粘合剂性能可能因表面粗糙度、制造缺陷或杂质而受损。先前研究探讨了阵列中分布缺陷和单个纤维缺陷的情况，但局部宏观缺陷的影响尚不清楚。通过离散机械模型的数值模拟，研究了单个圆形缺陷的大小和位置如何影响粘附力（F）与系统有效合规性（β）之间的关系，即F ∝ β^{-1/2}。发现边缘缺陷比中心缺陷更破坏，因为它们作为预裂纹，放大粘合剂边缘的应力集中，加速裂纹样失效。因此，已建立的粘附缩放定律得以保持，缺陷仅减少有效接触面积。相比之下，中心缺陷改变了脱附力学。通过将接触几何形状转变为环形，它促进了剩余纤维的更均匀负载共享，并缓解了边缘主导的失效机制。这种变化使粘附强度对系统合规性更不敏感，如更不负面的缩放指数所示。这两种模式之间的过渡似乎发生在缺陷边界与粘合剂边界相接时。这些结果为仿生纤维粘合剂的设计、工程和质量控制提供了实用指导。
英文摘要：
The performance of bio-inspired fibrillar adhesives can be compromised by surface roughness, manufacturing imperfections or impurities. Previous studies investigated the cases of distributed defects on the array, and defects at the level of single fibrils. However, the influence of localized, macroscopic defects remains largely unexplored. Using numerical simulations of a discrete mechanical model for a fibrillar adhesive with a thick backing layer, we investigate how the size and location of a single circular defect affect the established scaling law between the adhesion force ($F$) and the effective compliance of the system ($β$), \ie, $F \propto β^{-1/2}$. We find that edge defects are generally more detrimental than central ones, as they act as pre-cracks that amplify stress concentrations at the adhesive's edge, accelerating a crack-like failure. Consequently, the established adhesion scaling law is preserved, with the defect only reducing the effective contact area. In contrast, a central defect fundamentally alters the mechanics of detachment. By transforming the contact geometry into an annulus, it promotes more uniform load sharing across the remaining fibrils and mitigates the edge-dominated failure mechanism. This change makes the adhesive strength less sensitive to the compliance of the system, as reflected by a less negative scaling exponent. The transition between these two regimes appears to occur for defects whose boundary merges with the one of the adhesive. These results provide practical guidance for the design, engineering and quality control of bio-inspired fibrillar adhesives.
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。
