A Novel Videography Method for Generating Crack-Extension Resistance Curves in Small Bone Samples

Assessment of bone quality is an emerging solution for quantifying the effects of bone pathology or treatment. Perhaps one of the most important parameters characterising bone quality is the toughness behaviour of bone. Particularly, fracture toughness, is becoming a popular means for evaluating bone quality. The method is moving from a single value approach that models bone as a linear-elastic material (using the stress intensity factor, K) towards full crack extension resistance curves (R-curves) using a non-linear model (the strain energy release rate in J-R curves). However, for explanted human bone or small animal bones, there are difficulties in measuring crack-extension resistance curves due to size constraints at the millimetre and sub-millimetre scale. This research proposes a novel “whitening front tracking” method that uses videography to generate full fracture resistance curves in small bone samples where crack propagation cannot typically be observed. Here we present this method on sharp edge notched samples (

骨质量评估是量化骨病变与治疗效果的新兴研究方向。表征骨质量的核心参数之一为骨骼的韧性行为，其中断裂韧性（Fracture Toughness）正成为评估骨质量的常用手段。相关评估方法正从将骨骼建模为线弹性材料的单值法（采用应力强度因子K），转向基于非线性模型的全裂纹扩展阻力曲线（R曲线）法，该方法以J-R曲线中的应变能释放率（Strain Energy Release Rate）为评价依据。然而，对于离体人骨或小型动物骨骼，由于受毫米乃至亚毫米级的尺寸限制，难以直接测量裂纹扩展阻力曲线（Crack-extension Resistance Curves）。本研究提出一种全新的「亮白前沿追踪（Whitening Front Tracking）」方法，该方法借助摄像技术，可在通常无法直接观测裂纹扩展的小型骨骼样本中生成完整的断裂阻力曲线。本研究以带锐边切口的试样为例展示该方法（