کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
811164 | 1469144 | 2011 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Armadillo armor: Mechanical testing and micro-structural evaluation Armadillo armor: Mechanical testing and micro-structural evaluation](/preview/png/811164.png)
The armadillo has a unique protective bony armor, called the osteoderm, which confers to its shell-like skin distinctive mechanical properties. The top layer of the shell is made out of a dark-brown keratin layer with bimodal size scales. Beneath the keratin layer, the osteoderm consists of hexagonal or triangular tiles having a composition that is the same as bone. The tiles are connected by non-mineralized collagen fibers, called Sharpey’s fibers. The tough and highly mineralized tiles have a tensile strength of approximately 20 MPa and toughness of around 1.1 MJ/m3. In comparison, the hydrated osteoderm has a lower tensile strength of ∼16MPa and a toughness of 0.5 MJ/m3. The tensile failure occurs by the stretching and rupture of the Sharpey’s fibers. In a specially designed punch test in which an individual tile is pushed out, the shear strength is ∼18MPa, close to the tensile strength of the osteoderm. This surprising result is interpreted in terms of deformation in the Sharpey’s fibers in the hydrated condition. The armadillo shell and a turtle shell are compared, with their corresponding similarities and differences.
Journal: Journal of the Mechanical Behavior of Biomedical Materials - Volume 4, Issue 5, July 2011, Pages 713–722