Suh J K, Bai S
Department of Orthopaedic Surgery, University of Pittsburgh, PA 15213, USA.
J Biomech Eng. 1998 Apr;120(2):195-201. doi: 10.1115/1.2798302.
The purpose of the present study was to develop a computationally efficient finite element model that could be useful for parametric analysis of the biphasic poroviscoelastic (BPVE) behavior of articular cartilage under various loading conditions. The articular cartilage was modeled as the BPVE mixture of a porous, linear viscoelastic, and incompressible solid and an inviscid and incompressible fluid. A finite element (FE) formulation of the BPVE model was developed using two different algorithms, the continuous and discrete spectrum relaxation functions for the viscoelasticity of the solid matrix. These algorithms were applied to the creep and stress relaxation responses to the confined compression of articular cartilage, and a comparison of their performances was made. It was found that the discrete spectrum algorithm significantly saved CPU time and memory, as compared to the continuous spectrum algorithm. The consistency analysis for the present FE formulation was performed in comparison with the IMSL, a commercially available numerical software package. It was found that the present FE formulation yielded consistent results in predicting model behavior, whereas the IMSL subroutine produced inconsistent results in the velocity field, and thereby in the strain calculation.
本研究的目的是开发一种计算效率高的有限元模型，该模型可用于在各种加载条件下对关节软骨的双相多孔粘弹性（BPVE）行为进行参数分析。关节软骨被建模为多孔、线性粘弹性和不可压缩固体与无粘性和不可压缩流体的BPVE混合物。使用两种不同的算法，即固体基质粘弹性的连续和离散谱松弛函数，开发了BPVE模型的有限元（FE）公式。将这些算法应用于关节软骨受限压缩的蠕变和应力松弛响应，并对它们的性能进行了比较。结果发现，与连续谱算法相比，离散谱算法显著节省了CPU时间和内存。与商业可用的数值软件包IMSL相比，对当前的有限元公式进行了一致性分析。结果发现，当前的有限元公式在预测模型行为方面产生了一致的结果，而IMSL子程序在速度场中产生了不一致的结果，从而在应变计算中也产生了不一致的结果。
