کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10230253 787 2005 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mechanistic aspects of fracture and R-curve behavior in human cortical bone
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Mechanistic aspects of fracture and R-curve behavior in human cortical bone
چکیده انگلیسی
An understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. In the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. The fracture toughness was found to rise linearly with crack extension (i.e., rising resistance- or R-curve behavior) with a mean crack-initiation toughness, K0 of ∼2 MPa√m for crack growth in the proximal-distal direction. Uncracked ligament bridging, which was observed in the wake of the crack, was identified as the dominant toughening mechanism responsible for the observed R-curve behavior. The extent and nature of the bridging zone was examined quantitatively using multi-cutting compliance experiments in order to assess the bridging zone length and estimate the bridging stress distribution. Additionally, time-dependent cracking behavior was observed at stress intensities well below those required for overload fracture; specifically, slow crack growth occurred at growth rates of ∼2×10−9 m/s at stress intensities ∼35% below the crack-initiation toughness. In an attempt to measure slower growth rates, it was found that the behavior switched to a regime dominated by time-dependent crack blunting, similar to that reported for dentin; however, such blunting was apparent over much slower time scales in bone, which permitted subcritical crack growth to readily take place at higher stress intensities.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biomaterials - Volume 26, Issue 2, January 2005, Pages 217-231
نویسندگان
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