TY - JOUR ID - 21815 TI - A parametric study on the mechanical role of fibrillar rotations in an articular cartilage finite element model JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Sajjadinia, S. S. AU - Haghpanahi, M. AD - Faculty of Computer Science, Free University of Bozen-Bolzano, 39100 Bozen-Bolzano, Italy AD - School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16846, Iran Y1 - 2021 PY - 2021 VL - 28 IS - 2 SP - 830 EP - 836 KW - Biomechanics KW - Articular cartilage KW - Fibrillar rotation KW - UMAT KW - Parametric finite element analysis DO - 10.24200/sci.2020.51785.2362 N2 - Collagen network is one of the articular cartilage (AC) vital components, which contributes to the depth-dependent and anisotropic response of the tissue. As it is computationally expensive to simulate all the structural details of the AC network, they were typically simplified in numerical analysis. In particular, the so-called arcade-like structure, which has been widely used in the previous complex simulations, does not capture the rotations of the fibrillar bundles. In this study, we investigate the role of such possible rotations in the AC mechanical response by a set of advanced, biphasic, and parametric finite element (FE) simulations of indentation tests. Our results unveil the influence of fibrillar rotation (FR) on the mechanical response by increasing the fibrillar stress while regionally affecting the stress in the upper layers of the AC tissue. On the contrary, the FR did not significantly alter the tissue elasticity, and consequently might be ignored safely in pure contact mechanical problems. It is concluded that the excessive FR might regionally increase the stress, which can have a degenerative effect on the collagen constituent, and therefore, should not be neglected in the corresponding future studies, in which the upper AC layers resist high permanent shear strains. UR - https://scientiairanica.sharif.edu/article_21815.html L1 - https://scientiairanica.sharif.edu/article_21815_50ac8f385a0c2db62e2d6fd440288051.pdf ER -