Theoretical Limits in Detachment Strength for Axisymmetric Bi-Material Adhesives
Theoretical Limits in Detachment Strength for Axisymmetric Bi-Material Adhesives
复制标题
轴对称双材料粘合剂剥离强度的理论极限
DOI：
10.1115/1.4052107
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
M. Bacca
中科院分区：
文献类型：
--
作者：
Farid H. Benvidi;M. Bacca
可逆干胶粘剂依赖于短距离分子间键，因此需要低弹性模量以符合粘附材料的表面粗糙度。而在外力作用下，软胶黏剂会积累应变能，应变能的释放会驱动界面缺陷的扩展，从而导致剥离。在所需的顺应性（表面一致性）和降低能量释放率（更好的强度）之间的权衡，可以通过具有软尖端和刚性背衬（RB）的双材料粘合剂来实现。这种设计策略在自然界的多个物种中被广泛观察到。然而，这些胶粘剂的脱离机制尚不完全清楚，其粘接强度的定量分析仍然缺失。基于线弹性断裂力学，分析了轴对称双材料胶粘剂的强度。我们观察到两种主要的剥离机制，即(i)中心裂纹扩展和（ii）边缘裂纹扩展。如果软尖端足够薄，则机制(i)起主导作用并提供稳定的裂纹扩展，从而使界面增韧。我们最终提供了这些粘合剂的最大理论强度，获得了不可压缩尖端的封闭形式估计。在某些情况下，最大粘接强度与裂纹尺寸无关，使界面具有容错性。最后，我们将我们的预测与文献中的实验进行了比较，并观察到良好的一致性。
Reversible dry adhesives rely on short-ranged intermolecular bonds, hence requiring a low elastic modulus to conform to the surface roughness of the adhered material. Under external loads, however, soft adhesives accumulate strain energy, which release drives the propagation of interfacial flaws prompting detachment. The trade-off between the required compliance, for surface conformity, and the desire for a reduced energy release rate, for better strength, can be achieved with a bi-material adhesive having a soft tip and a rigid backing (RB). This design strategy is widely observed in nature across multiple species. However, the detachment mechanisms of these adhesives are not completely understood and quantitative analysis of their adhesive strength is still missing. Based on linear elastic fracture mechanics (LEFM), we analyze the strength of axisymmetric bi-material adhesives. We observed two main detachment mechanisms, namely (i) center crack propagation and (ii) edge crack propagation. If the soft tip is sufficiently thin, mechanism (i) dominates and provides stable crack propagation, thereby toughening the interface. We ultimately provide the maximum theoretical strength of these adhesives obtaining closed-form estimation for an incompressible tip. In some cases, the maximum adhesive strength is independent of the crack size, rendering the interface flaw tolerant. We finally compare our prediction with experiments in the literature and observe good agreement.
影响因子：
9.5
作者：
Fischer SC;Arzt E;Hensel R
通讯作者：
Hensel R
影响因子：
5.3
作者：
Bahjepalli, Ram Gopal;Fischer, Sarah C. L.;Arzt, Eduard
通讯作者：
Arzt, Eduard
影响因子：
2.2
作者：
Hensel, Rene;McMeeking, Robert M.;Kossa, Attila
通讯作者：
Kossa, Attila