Li LePing, Buschmann M D, Shirazi-Adl A
BioSyntech Inc., Laval, Quebec, Canada.
Biorheology. 2002;39(1-2):89-96.
Collagen fibril reinforcement was incorporated into a nonlinear poroelastic model for articular cartilage in unconfined compression. It was found that the radial fibrils play a predominant role in the transient mechanical behavior but a less important role in the equilibrium response of cartilage. The radial fibrils are in tension and can be highly stressed during compression, in contrast to low compressive stresses in all directions for the proteoglycan matrix after a small initial compression. The strain dependent fibril stiffening produces strong nonlinear transient response; the fibrils provide extra stiffness to balance a rising fluid pressure and to restrain stress increase in the proteoglycans. The fibril reinforcement, induced by the fluid pressure and flow, also accounts for a complex pattern of strain-magnitude and strain-rate dependence of cartilage stiffness.
在无侧限压缩情况下，将胶原纤维增强作用纳入关节软骨的非线性多孔弹性模型中。研究发现，径向纤维在瞬态力学行为中起主要作用，但在软骨的平衡响应中作用较小。与初始小压缩后蛋白聚糖基质在所有方向上的低压缩应力相反，径向纤维处于拉伸状态，在压缩过程中会承受高应力。应变依赖性纤维硬化产生强烈的非线性瞬态响应；纤维提供额外的刚度以平衡不断上升的流体压力并抑制蛋白聚糖中的应力增加。由流体压力和流动引起的纤维增强作用，也解释了软骨刚度对应变大小和应变率依赖性的复杂模式。
