Microscale fiber network alignment affects macroscale failure behavior in simulated collagen tissue analogs.
Microscale fiber network alignment affects macroscale failure behavior in simulated collagen tissue analogs.
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DOI：
10.1115/1.4023411
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发表时间：
2013-02
期刊：
影响因子：
--
通讯作者：
Barocas VH
中科院分区：
文献类型：
--
作者：
Hadi MF;Barocas VH
组织的微观结构决定了其在较大长度尺度上的破坏特性，但在天然和工程化软组织(如囊韧带、主动脉瘤或血管移植物)中，微观结构与宏观破坏之间的具体关系已被证明是难以捉摸的。在这项研究中，我们模拟了胶原凝胶组织类似物中微观纤维排列的变化，以了解它们对宏观损伤和失败结果的影响。本研究采用多尺度有限元模型对胶原基材料的损伤和破坏进行了研究。该模型依赖于微观结构代表性体积元素(RVEs)，它由随机生成的离散型I型胶原纤维网络组成。在有缺口的狗骨几何结构的宏观有限元模型中，RVEs内以及RVEs层之间的纤维排列是不同的。比较狗骨单轴伸展至破坏时，不同排列情况下纤维的宏观拉伸和微观响应。具有较大平行于拉伸方向的纤维排列的网络在较小的应变下失败(失效时的格林应变减少6-22%)，但与具有垂直于拉伸方向排列的纤维的网络相比，握力较大(增加28-60%)。交错层层的网络对齐(对齐+/−与延伸方向成45度)在较小的应变下会失败，但与使用一种光纤对齐类型产生的握力相比，会产生更大的握力。综上所述，纤维排列引起的微观结构的变化产生了不同的宏观破坏趋势。总而言之，这些发现可能在组织工程和软组织生物力学领域具有重要意义。
A tissue's microstructure determines its failure properties at larger length scales, but the specific relationship between microstructure and macroscopic failure in native and engineered soft tissues (such as capsular ligaments, aortic aneurysms, or vascular grafts) has proven elusive. In this study, variations in the microscale fiber alignment in collagen gel tissue analogs were modeled in order to understand their effects on macroscale damage and failure outcomes. The study employed a multiscale finite-element (FE) model for damage and failure in collagen-based materials. The model relied on microstructural representative volume elements (RVEs) that consisted of stochastically-generated networks of discrete type-I collagen fibers. Fiber alignment was varied within RVEs as well as between layers of RVEs in a macroscopic FE model of a notched dogbone geometry. The macroscale stretch and the microscale response of fibers for each of the differently aligned cases was compared as the dogbone was uniaxially extended to failure. Networks with greater fiber alignment parallel to the direction of extension failed at smaller strains (with a 6–22% reduction in Green strain at failure) but greater grip forces (28–60% increase) than networks with fibers aligned perpendicular to the extension. Alternating layers of crisscrossed network alignments (aligned +/− 45 degrees to the direction of extension) failed at smaller strains but at greater grip forces than those created using one fiber alignment type. In summary, variations in microscale structure via fiber alignment produced different macroscale failure trends. These findings, to conclude, may be significant in the realm of tissue engineering and in soft tissue biomechanics.
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影响因子：
14
作者：
D'Amore A;Stella JA;Wagner WR;Sacks MS
通讯作者：
Sacks MS
影响因子：
4.9
作者：
Sander, E. A.;Barocas, V. H.
通讯作者：
Barocas, V. H.
影响因子：
3.9
作者：
Hamed, Elham;Jasiuk, Iwona;Liszka, Tadeusz
通讯作者：
Liszka, Tadeusz
影响因子：
3.3
作者：
Ito, S;Ingenito, EP;Suki, B
通讯作者：
Suki, B
DOI：
10.1115/1.4007097
发表时间：
2012-09-01
影响因子：
1.7
作者：
Hadi, Mohammad F.;Sander, Edward A.;Barocas, Victor H.
通讯作者：
Barocas, Victor H.