A computational study of invariant I5 in a nearly incompressible transversely isotropic model for white matter

JOURNAL OF BIOMECHANICS

卷:57

Article

Feng, Yuan^1,2  Qiu, Suhao^1,3  Xia, Xiaolong^1,3  Ji, Songbai⁴  Lee, Chung-Hao^5,6 

[1] Soochow Univ, Ctr Mol Imaging & Nucl Med, Collaborat Innovat Ctr Radiat Med, Sch Radiol & Interdisciplinary Sci RAD X,Jiangsu, Suzhou 215123, Jiangsu, Peoples R China

[2] Soochow Univ, Sch Mech & Elect Engn, Suzhou 215021, Jiangsu, Peoples R China

[3] Soochow Univ, Sch Elect & Informat Engn, Suzhou 215021, Jiangsu, Peoples R China

[4] Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA

[5] Univ Oklahoma, Sch Aerosp & Mech Engn, Norman, OK 73019 USA

[6] Univ Texas Austin, Inst Computat Engn & Sci, Austin, TX 78712 USA

关键词: White matter;    Biomechanics;    Constitutive modeling of biomaterials;    Finite element methods;    Tissue mechanics;   

DOI  :  10.1016/j.jbiomech.2017.03.025

来源: Elsevier

【 摘 要 】

The aligned axonal fiber bundles in white matter make it suitable to be modeled as a transversely isotropic material. Recent experimental studies have shown that a minimal form, nearly incompressible transversely isotropic (MITI) material model, is capable of describing mechanical anisotropy of white matter. Here, we used a finite element (FE) computational approach to demonstrate the significance of the fifth invariant (Is) when modeling the anisotropic behavior of white matter in the large-strain regime. We first implemented and validated the MITI model in an FE simulation framework for large deformations. Next, we applied the model to a plate-hole structural problem to highlight the significance of the invariant Is by comparing with the standard fiber reinforcement (SFR) model. We also compared the two models by fitting the experiment data of asymmetric indentation, shear test, and uniaxial stretch of white matter. Our results demonstrated the significance of is in describing shear deformation/anisotropy, and illustrated the potential of the MITI model to characterize transversely isotropic white matter tissues in the large-strain regime. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free