Poisson's Contraction and Fiber Kinematics in Tissue: Insight From Collagen Network Simulations
Poisson's Contraction and Fiber Kinematics in Tissue: Insight From Collagen Network Simulations
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组织中的泊松收缩和纤维运动学：来自胶原网络模拟的见解
DOI：
10.1115/1.4038428
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Islam, M. R.
中科院分区：
文献类型：
--
作者：
Picu, R. C.;Deogekar, S.;Islam, M. R.
结缔组织力学是高度非线性的，表现出强烈的泊松效应，并与显着的胶原纤维重排。虽然应力-应变行为的一般特征已被广泛讨论，泊松效应得到较少的关注。一般来说，微观纤维网络力学和宏观实验观察之间的关系仍然很难定义。目前的工作的目标是提供更多的洞察这种关系。为此，随机胶原蛋白网络模型的结果进行了比较重建胶原蛋白凝胶，小鼠皮肤真皮，和人类羊膜的实验数据。注意力是专门的机制，导致在实验中观察到的大泊松效应。结果表明，增量泊松收缩是直接相关的优先胶原蛋白的取向。实验观察到的下降的增量泊松比在较大的应变与横向的加载方向的纤维的限制效果，并有助于承载。胶原蛋白取向的速率在小应变下增加，达到最大值，并且在较大应变下降低。该曲线中的峰值与网络变形从小应变下的弯曲主导向大应变下的轴向主导的转变相关联。还讨论了纤维弯曲度对网络力学的影响，并比较了双轴和单轴加载响应。
Connective tissue mechanics is highly nonlinear, exhibits a strong Poisson's effect, and is associated with significant collagen fiber re-arrangement. Although the general features of the stress–strain behavior have been discussed extensively, the Poisson's effect received less attention. In general, the relationship between the microscopic fiber network mechanics and the macroscopic experimental observations remains poorly defined. The objective of the present work is to provide additional insight into this relationship. To this end, results from models of random collagen networks are compared with experimental data on reconstructed collagen gels, mouse skin dermis, and the human amnion. Attention is devoted to the mechanism leading to the large Poisson's effect observed in experiments. The results indicate that the incremental Poisson's contraction is directly related to preferential collagen orientation. The experimentally observed downturn of the incremental Poisson's ratio at larger strains is associated with the confining effect of fibers transverse to the loading direction and contributing little to load bearing. The rate of collagen orientation increases at small strains, reaches a maximum, and decreases at larger strains. The peak in this curve is associated with the transition of the network deformation from bending dominated, at small strains, to axially dominated, at larger strains. The effect of fiber tortuosity on network mechanics is also discussed, and a comparison of biaxial and uniaxial loading responses is performed.