Abstract We investigate the influence of the coordination of cross-links on the plastic (i.e., permanent) deformation in cross-linked fiber bundles. Yield strain and strength as well as the resilience are studied as a function of cross-linker and grafting density. It is found that classical twofold coordinated cross-links lead to a pronounced strain concentration in the system, while cross-links with higher coordination allow for a more homogeneous load transfer through the system. This results in inferior mechanical properties related to plastic behavior in the first system compared to the latter. Particularly, in twofold coordinated systems, the resilience shows a non-monotonic behavior with respect to cross-linker density. This means that inserting always more and stronger cross-links do not necessarily improve the mechanical performance of a material. These findings may help to interpret experimental findings on the fracture energy in hydro-gels cross-linked with zinc ions.

中文翻译：

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纤维束中交联的高度协调可防止局部应变集中

摘要 我们研究了交联配位对交联纤维束塑性（即永久）变形的影响。研究了作为交联剂和接枝密度的函数的屈服应变和强度以及回弹性。发现经典的双重协调交联导致系统中明显的应变集中，而具有更高协调的交联允许通过系统更均匀的负载转移。与后者相比，这导致第一个系统中与塑性行为相关的机械性能较差。特别是，在双重协调系统中，弹性表现出相对于交联剂密度的非单调行为。这意味着总是插入更多和更强的交联并不一定会改善材料的机械性能。这些发现可能有助于解释与锌离子交联的水凝胶中断裂能的实验结果。