کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10159830 59 2013 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales
چکیده انگلیسی
The alligator gar is a large fish with flexible armor consisting of ganoid scales. These scales contain a thin layer of ganoine (microhardness ∼2.5 GPa) and a bony body (microhardness ∼400 MPa), with jagged edges that provide effective protection against predators. We describe here the structure of both ganoine and bony foundation and characterize the mechanical properties and fracture mechanisms. The bony foundation is characterized by two components: a mineralized matrix and parallel arrays of tubules, most of which contain collagen fibers. The spacing of the empty tubules is ∼60 μm; the spacing of those filled with collagen fibers is ∼7 μm. Using micromechanical testing of such scales in a variable-pressure scanning electron microscope, we identify interactions between propagating cracks and the microstructure, and show that the toughness of the scales increases with crack extension in a classical resistance-curve response from the activation of extrinsic toughening mechanisms. We demonstrate how mechanical damage evolves in these structures, and further identify that the reinforcement of the mineral by the network of collagen fibers is the principal toughening mechanism resisting such damage. Additionally, we define the anisotropy of the toughness of the scales and relate this to the collagen fiber orientation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Biomaterialia - Volume 9, Issue 4, April 2013, Pages 5876-5889
نویسندگان
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