Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208-3111, USA.
J Mech Behav Biomed Mater. 2011 Feb;4(2):190-211. doi: 10.1016/j.jmbbm.2010.11.006. Epub 2010 Nov 24.
Nacre, the iridescent material found in Abalone shells, exhibits remarkable strength and toughness despite its composition of over 95% brittle ceramic. Its hierarchical structure over multiple length scales gives rise to its increase in toughness despite its material composition. In this work we develop a computational model of composites incorporating key morphological features of nacre's microstructure. By conducting a parametric analysis we are able to determine an optimal geometry that increases energy dissipation over 70 times. We discuss the contribution of varying ceramic strengths and size effect to see how this affects the overall performance of the composite. We then compare our simulations to experiments performed on a material possessing the same microstructure investigated computationally. For both simulations and experiments we show that our optimal geometry corresponds to that of natural nacre indicating the importance of specifically incorporating nacre's key morphological and constituent features. This combination of simulations and experiments gives great insight to the delicate interplay between material parameters and microstructure showing that if we optimally combine all aspects, we can develop novel synthetic materials with superior performance.
珍珠母，一种存在于鲍鱼壳内的具有虹彩效果的物质，尽管其组成超过 95%为易碎陶瓷，但却具有显著的强度和韧性。它的多层次结构在多个长度尺度上增加了韧性，尽管其材料组成是脆性的。在这项工作中，我们开发了一种包含珍珠母微观结构关键形态特征的复合材料计算模型。通过进行参数分析，我们能够确定一个最佳的几何形状，使能量耗散增加超过 70 倍。我们讨论了变化的陶瓷强度和尺寸效应对整体性能的影响。然后，我们将模拟结果与具有相同微观结构的实验进行了比较。对于模拟和实验，我们都表明我们的最佳几何形状对应于天然珍珠母的几何形状，这表明了特别纳入珍珠母的关键形态和组成特征的重要性。这种模拟和实验的结合为材料参数和微观结构之间的微妙相互作用提供了深刻的见解，表明如果我们最优地结合所有方面，我们可以开发具有优异性能的新型合成材料。
