A FINITE DEFORMATION-THEORY FOR CARTILAGE AND OTHER SOFT HYDRATED CONNECTIVE TISSUES .1. EQUILIBRIUM RESULTS
A FINITE DEFORMATION-THEORY FOR CARTILAGE AND OTHER SOFT HYDRATED CONNECTIVE TISSUES .1. EQUILIBRIUM RESULTS
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DOI：
10.1016/0021-9290(90)90348-7
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发表时间：
1990-01-01
影响因子：
2.4
通讯作者：
MOW, VC
中科院分区：
文献类型：
--
作者：
KWAN, MK;LAI, WM;MOW, VC
确定有限变形条件下关节软骨的有效应力-应变关系是建立滑膜关节润滑模型的前提。在关节中的高应变率和/或高应力的生理条件下，软骨中发生大应变。一个有限变形理论有效描述软骨，以及其他软水合结缔组织在大负荷下，已经开发。该理论基于选择一个特定的Helmholtz能量函数，该能量函数满足有限弹性理论中建立的广义Coleman-Noll（GCNO）条件和Baker-Ericksen（B-E）不等式。此外，有限变形双相理论还考虑了应变相关孔隙度和渗透率的影响。这些非线性效应对于正确描述关节软骨的生物力学行为是必不可少的，即使应变率很低，应变是无穷小的。有限变形理论描述了在一维有限压缩实验中观察到的软骨在平衡状态下的大应变行为，并且在无限小应变和慢应变速率条件下，它简化为线性双相理论。利用这一理论，我们已经确定了在平衡状态下的大应变条件下的人和牛关节软骨的材料系数。理论与实验结果比较很好。
The determination of valid stress-strain relations for articular cartilage under finite deformation conditions is a prerequisite for constructing models for synovial joint lubrication. Under physiological conditions of high strain rates and/or high stresses in the joint, large strains occur in cartilage. A finite deformation theory valid for describing cartilage, as well as other soft hydrated connective tissues under large loads, has been developed. This theory is based on the choice of a specific Helmholtz energy function which satisfies the generalized Coleman-Noll (GCNO) condition and the Baker-Ericksen (B-E) inequalities established in finite elasticity theory. In addition, the finite deformation biphasic theory includes the effects of strain-dependent porosity and permeability. Thesae nonlinear effects are essential for properly describing the biomechanical behavior of articular cartilage, even when strain rates are low and strains are infinitesimal. The finite deformation theory describes the large strain behavior of cartilage observed in one-dimensional confined compression experiments at equilibrium, and it reduces to the linear biphasic theory under infinitesimal strain and slow strain rate conditions. Using this theory, we have determined the material coefficients of both human and bovine articular cartilages under large strain conditions at equilibrium. The theory compares very well with experimental results.