Determination of material models for arterial walls from uniaxial extension tests and histological structure
Determination of material models for arterial walls from uniaxial extension tests and histological structure
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DOI：
10.1016/j.jtbi.2005.05.006
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发表时间：
2006-01-21
影响因子：
2
通讯作者：
Holzapfel, GA
中科院分区：
文献类型：
--
作者：
Holzapfel, GA
提出了一种方法，允许根据单轴试验和组织结构数据(包括组织的纤维取向)确定材料模型。采用Neo-Hookean应变能函数和冯型应变能函数相结合的方法，推导出了严格的局部凸性和纤维择优取向下对本构参数施加的不等式约束。给出了冯型模型如何获得唯象模型固有的伪结构特征；明确地提供了纤维结构与冯型模型参数之间的关联。为了应用所提出的方法，从具有非动脉粥样硬化性内膜增厚的人的主动脉内膜、中层和外膜获得了准静态单轴拉伸试验；来自组织学分析的每个主动脉组织的结构信息被记录下来。数据显示，与中膜和外膜相比，内膜样本具有显著的厚度、承载能力和硬度。通过罚函数法求解约束问题，确定了各主动脉组织层的本构参数；提出了一种估计合适起始值的新方法。最后，通过将模型数据与单轴拉伸试验和组织图像分析的数据进行比较，显示了材料模型的预测性和有效性。(C)2005爱思唯尔有限公司。保留所有权利。
An approach is proposed that allows the determination of material models from uniaxial tests and histostructural data including fiber orientation of the tissue. A combination of neo-Hookean and Fung-type strain-energy functions is utilized, and inequality constraints imposed on the constitutive parameters are derived providing strict local convexity and preferred fiber orientations. It is shown how the Fung-type model gets a pseudo-structural aspect inherent in the phenomenological model; a correlation between the fiber structure and the parameters of the Fung-type model is explicitly provided. In order to apply the proposed approach, quasistatic uniaxial extension tests of preconditioned prepared strips from the intima, media and adventitia of a human aorta with nonatherosderotic intimal thickening are acquired in axial and circumferential directions; structural information from histological analyses for each aortic tissue are documented. Data reveal a remarkable thickness, load-bearing capacity and stiffness of the intimal samples in comparison with the media and adventitia. Constitutive parameters for each aortic tissue layer are determined by solving the constrained problem using a penalty function method; a new approach for the estimation of appropriate start values is proposed. Finally, the predictivity and efficacy of the material models is shown by comparing model data with data from the uniaxial extension tests and histological image analyses. (c) 2005 Elsevier Ltd. All rights reserved.