Wang Shuolun, Hatami-Marbini Hamed
Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607.
Mechanical and Industrial Engineering, University of Illinois at Chicago, 2033 Engineering Research Facility, 842 W. Taylor Street, Chicago, IL 60607.
J Biomech Eng. 2021 Mar 1;143(3). doi: 10.1115/1.4048401.
The cornea, the transparent tissue in the front of the eye, along with the sclera, plays a vital role in protecting the inner structures of the eyeball. The precise shape and mechanical strength of this tissue are mostly determined by the unique microstructure of its extracellular matrix. A clear picture of the 3D arrangement of collagen fibrils within the corneal extracellular matrix has recently been obtained from the secondary harmonic generation images. However, this important information about the through-thickness distribution of collagen fibrils was seldom taken into account in the constitutive modeling of the corneal behavior. This work creates a generalized structure tensor (GST) model to investigate the mechanical influence of collagen fibril through-thickness distribution. It then uses numerical simulations of the corneal mechanical response in inflation experiments to assess the efficacy of the proposed model. A parametric study is also done to investigate the influence of model parameters on numerical predictions. Finally, a brief comparison between the performance of this new constitutive model and a recent angular integration (AI) model from the literature is given.
角膜是眼球前部的透明组织，与巩膜一起在保护眼球内部结构方面发挥着至关重要的作用。该组织精确的形状和机械强度主要由其细胞外基质独特的微观结构决定。最近，通过二次谐波产生图像获得了角膜细胞外基质中胶原纤维三维排列的清晰图像。然而，在角膜行为的本构模型中，很少考虑到关于胶原纤维厚度分布的这一重要信息。这项工作创建了一个广义结构张量（GST）模型来研究胶原纤维厚度分布的力学影响。然后，通过充气实验中角膜力学响应的数值模拟来评估所提出模型的有效性。还进行了参数研究，以研究模型参数对数值预测的影响。最后，对这个新的本构模型与文献中最近的角积分（AI）模型的性能进行了简要比较。
