Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
J R Soc Interface. 2012 Aug 7;9(73):1787-96. doi: 10.1098/rsif.2011.0910. Epub 2012 Feb 15.
Bird beaks are layered structures, which contain a bony core and an outer keratin layer. The elastic moduli of this bone and keratin were obtained in a previous study. However, the mechanical role and interaction of both materials in stress dissipation during seed crushing remain unknown. In this paper, a multi-layered finite-element (FE) model of the Java finch's upper beak (Padda oryzivora) is established. Validation measurements are conducted using in vivo bite forces and by comparing the displacements with those obtained by digital speckle pattern interferometry. Next, the Young modulus of bone and keratin in this FE model was optimized in order to obtain the smallest peak von Mises stress in the upper beak. To do so, we created a surrogate model, which also allows us to study the impact of changing material properties of both tissues on the peak stresses. The theoretically best values for both moduli in the Java finch are retrieved and correspond well with previous experimentally obtained values, suggesting that material properties are tuned to the mechanical demands imposed during seed crushing.
鸟类的喙是分层结构，包含一个骨核心和一个外部角蛋白层。在之前的研究中已经获得了这种骨骼和角蛋白的弹性模量。然而，在种子破碎过程中，这两种材料的力学作用和相互作用在应力耗散中的作用仍不清楚。在本文中，建立了 Java 雀（Padda oryzivora）上喙的多层有限元（FE）模型。通过体内咬合力测量和与数字散斑干涉测量获得的位移进行验证。接下来，优化了该 FE 模型中骨骼和角蛋白的杨氏模量，以获得上喙中的最小峰值 von Mises 应力。为此，我们创建了一个替代模型，该模型还可以研究改变两种组织的材料特性对上峰值应力的影响。从理论上得出了 Java 雀的这两种模量的最佳值，与之前通过实验获得的值非常吻合，这表明材料特性是针对在种子破碎过程中施加的力学要求进行调整的。
