Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System, Tianjin, China.
School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China.
J Healthc Eng. 2017;2017:2306160. doi: 10.1155/2017/2306160. Epub 2017 Jun 12.
To investigate the mechanical responses of microdefect articular cartilage under rolling load and find out the failure rule.
Rolling load was applied to the porcine articular cartilage samples with rectangular notches of different depths. The displacement and strain near the notches were obtained by the noncontact digital image correlation technique.
The strain value and peak frequency around the notch increased; the maximum equivalent strain value could be observed at both bottom corners of the notch; the equivalent strain value first increased and then decreased at the points in the superficial and middle layers with the increase of rolling velocity; the points in the deep layer were less affected by rolling velocity; the equivalent strain value of the points in the superficial layer declined after rising with the increase of defect depth, while a decreased trend could be found for the points in the middle and deep layers.
The shear strain, which rose with the increase in defect depth, was the main factor in cartilage destruction. The cartilage tended to be destructed firstly at the bottom corner of the defect. Rolling velocity showed significant effects on superficial and middle layers. Cartilage had the ability to resist destruction.
研究微缺陷关节软骨在滚动载荷下的力学响应，找出失效规律。
对具有不同深度矩形缺口的猪关节软骨样本施加滚动载荷。通过非接触数字图像相关技术获得缺口附近的位移和应变。
缺口周围的应变值和峰值频率增加；在缺口的两个底角处可以观察到最大等效应变值；随着滚动速度的增加，在表层和中层的点处，等效应变值先增加后减少；深层的点受滚动速度的影响较小；随着缺陷深度的增加，表层点的等效应变值先上升后下降，而中层和深层点则呈下降趋势。
随着缺陷深度的增加而增加的剪切应变是软骨破坏的主要因素。软骨首先倾向于在缺陷的底部角落处被破坏。滚动速度对表层和中层有显著影响。软骨具有抵抗破坏的能力。
