Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B2020 Antwerpen, Belgium.
J R Soc Interface. 2012 Jun 7;9(71):1381-8. doi: 10.1098/rsif.2011.0667. Epub 2011 Nov 16.
In recent years, there has been a surge in the development of finite-element (FE) models aimed at testing biological hypotheses. For example, recent modelling efforts suggested that the beak in Darwin's finches probably evolved in response to fracture avoidance. However, knowledge of the material properties of the structures involved is crucial for any model. For many biological structures, these data are not available and may be difficult to obtain experimentally given the complex nature of biological structures. Beaks are interesting as they appear to be highly optimized in some cases. In order to understand the biomechanics of this small and complex structure, we have been developing FE models that take into account the bilayered structure of the beak consisting of bone and keratin. Here, we present the results of efforts related to the determination and validation of the elastic modulus of bone and keratin in bird beaks. The elastic moduli of fresh and dried samples were obtained using a novel double-indentation technique and through an inverse analysis. A bending experiment is used for the inverse analysis and the validation of the measurements. The out-of-plane displacements during loading are measured using digital speckle pattern interferometry.
近年来，旨在检验生物学假设的有限元（FE）模型发展迅速。例如，最近的建模工作表明，达尔文雀的喙可能是为了避免骨折而进化的。然而，对于任何模型来说，了解所涉及结构的材料特性都是至关重要的。对于许多生物结构来说，这些数据不可用，并且由于生物结构的复杂性，可能难以通过实验获得。喙很有趣，因为在某些情况下它们似乎是高度优化的。为了了解这个小型复杂结构的生物力学特性，我们一直在开发有限元模型，这些模型考虑了由骨和角蛋白组成的喙的双层结构。在这里，我们介绍了与确定和验证鸟喙中骨和角蛋白的弹性模量有关的结果。使用一种新颖的双压痕技术和反分析方法获得了新鲜和干燥样本的弹性模量。反分析和测量验证使用弯曲实验。使用数字散斑干涉测量法测量加载过程中的面外位移。
