Wagner Hanoch Daniel
Weizmann Institute of Science, Rehovot 7628604, Israel.
Materials (Basel). 2021 Nov 13;14(22):6855. doi: 10.3390/ma14226855.
Compared with their monolithic version, layered structures are known to be beneficial in the design of materials, especially ceramics, providing enhanced fracture toughness, mechanical strength, and overall reliability. This was proposed in recent decades and extensively studied in the engineering literature. The source of the property enhancement is the ability of layered structures to deflect and often arrest propagating cracks along internal interfaces between layers. Similar crack-stopping abilities are found in nature for a broad range of fibrillary layered biological structures. Such abilities are largely governed by complex architectural design solutions and geometries, which all appear to involve the presence of various types of internal interfaces at different structural levels. The simultaneous occurrence at several scales of different types of interfaces, designated here as hierarchical interfaces, within judiciously designed layered composite materials, is a powerful approach that constrains cracks to bifurcate and stop. This is concisely described here using selected biological examples, potentially serving as inspiration for alternative designs of engineering composites.
与整体结构相比，层状结构在材料设计中，尤其是在陶瓷材料设计中具有优势，能够提高断裂韧性、机械强度和整体可靠性。这一观点在近几十年被提出，并在工程文献中得到广泛研究。性能增强的根源在于层状结构能够使扩展裂纹沿着层间的内部界面发生偏转并常常使其停止扩展。在自然界中，广泛的纤维状层状生物结构也具有类似的止裂能力。这些能力在很大程度上受复杂的结构设计方案和几何形状的支配，而这些设计方案和几何形状似乎都涉及到不同结构层次上各种类型内部界面的存在。在经过精心设计的层状复合材料中，不同类型的界面（这里称为分级界面）在多个尺度上同时出现，是一种强大的方法，它能限制裂纹分叉并停止扩展。这里通过选取一些生物实例对此进行简要描述，这些实例可能为工程复合材料的替代设计提供灵感。
