Farquhar T, Dawson P R, Torzilli P A
Sibley School of Mechanical and Aerospace, Cornell University, Ithaca, NY 14853.
J Biomech Eng. 1990 Nov;112(4):414-25. doi: 10.1115/1.2891205.
A constitutive model for articular cartilage is developed to study directional load sharing within the soft biological tissue. Cartilage is idealized as a composite structure whose static mechanical response is dominated by distortion of a sparse fibrous network and by changes in fixed charge density. These histological features of living cartilage are represented in a microstructural analog of the tissue, linking the directionality of mechanical stiffness to the orientation of microstructure. The discretized 'model tissue' is used to define a stiffness tensor relating drained stress and strain over a regime of large deformation. The primary goal of this work was to develop a methodology permitting more complete treatment of anisotropy in the stiffness of cartilage. The results demonstrate that simple oriented microscopic behaviors can combine to produce complicated larger scale response. For the illustrative example of a homogeneous specimen subjected to confined compression, the model predicts a nonlinear anisotropic drained response, with inherent uncertainty at cellular size scales.
为研究这种柔软生物组织内的方向载荷分担情况，开发了一种关节软骨本构模型。软骨被理想化地视为一种复合结构，其静态力学响应主要由稀疏纤维网络的变形和固定电荷密度的变化主导。活软骨的这些组织学特征在该组织的微观结构模拟物中得以体现，将机械刚度的方向性与微观结构的取向联系起来。离散化的“模型组织”用于定义一个刚度张量，该张量在大变形范围内将排水应力和应变联系起来。这项工作的主要目标是开发一种方法，以便更全面地处理软骨刚度中的各向异性。结果表明，简单的定向微观行为可以结合起来产生复杂的更大尺度响应。对于承受侧限压缩的均匀试样这个示例，该模型预测了一种非线性各向异性排水响应，在细胞尺寸尺度上存在固有不确定性。
