Kelly P A, O'Connor J J
Oxford Orthopaedic Engineering Centre, Nuffield Orthopaedic Centre, Headington.
Proc Inst Mech Eng H. 1996;210(1):39-49. doi: 10.1243/PIME_PROC_1996_210_389_02.
A model of articular cartilage suffering rapidly applied loads and containing splits and fissures is presented. The possibility of cracks propagating through the cartilage collagen network is analysed using elastic fracture mechanics. Cracks are modelled using the distributed dislocation technique and the crack tip stress intensity factors are thereby evaluated. The mode I (tensile) stress intensity factors are generally much larger than the mode II (shearing) factors for cracks at the articular surface and close to, and at oblique angles to, the cartilage-bone interface, two regions where cartilage cracks have been observed. This suggests an opening, tensile mode of failure. The mode II factors are larger for cracks running along the interface. The rapidly loaded cracked cartilage model may explain the splits observed in osteoarthrotic cartilage.
提出了一种承受快速加载且包含裂缝和裂隙的关节软骨模型。使用弹性断裂力学分析了裂缝在软骨胶原网络中扩展的可能性。采用分布位错技术对裂缝进行建模，从而评估裂缝尖端的应力强度因子。对于关节表面以及靠近软骨 - 骨界面并与之呈斜角的裂缝（已观察到软骨裂缝的两个区域），I 型（拉伸）应力强度因子通常远大于 II 型（剪切）因子。这表明存在一种张开的拉伸破坏模式。对于沿界面延伸的裂缝，II 型因子更大。快速加载的裂缝软骨模型可能解释了在骨关节炎软骨中观察到的裂缝。
