Constitutive formulations for the mechanical investigation of colonic tissues
Constitutive formulations for the mechanical investigation of colonic tissues
复制标题
DOI：
10.1002/jbm.a.34787
复制
发表时间：
2014-05-01
影响因子：
4.9
通讯作者：
Natali, Arturo N.
中科院分区：
文献类型：
--
作者：
Carniel, Emanuele Luigi;Gramigna, Vera;Natali, Arturo N.
为描述结肠组织的力学行为提供了本构框架，作为开发结肠结构数值模型的基本工具。本构分析是通过多学科方法进行的，需要实验和计算能力之间的合作。初步调查与组织组织学的回顾有关。组织的复杂结构和纤维元素的特殊分布导致了非线性力学行为和各向异性响应。力学性能的识别需要根据不同的加载情况，按照不同的加载方向进行力学试验。由于结肠结构具有典型的功能性，因此通过拉伸试验来研究组织力学，这些拉伸试验是在新鲜的猪结肠带绦虫和钩虫标本上进行的。结合组织学研究和力学试验结果，在纤维增强复合材料理论中提出了一种特殊的超弹性框架。通过对试验结果的反分析，定义了用于确定本构参数的初步解析公式。建立了考虑结肠结构实际构型的试件的有限元模型，以验证结果的质量。实验结果与数值模型结果吻合较好，表明本构方程和参数是可靠的。最后，发展的本构分析使识别不同结肠组织的力学行为和特性成为可能。(C)2013 Wiley期刊，Inc.生物材料资源A部分：102A：1243-1254,2014。
A constitutive framework is provided for the characterization of the mechanical behavior of colonic tissues, as a fundamental tool for the development of numerical models of the colonic structures. The constitutive analysis is performed by a multidisciplinary approach that requires the cooperation between experimental and computational competences. The preliminary investigation pertains to the review of the tissues histology. The complex structural configuration of the tissues and the specific distributions of fibrous elements entail the nonlinear mechanical behavior and the anisotropic response. The identification of the mechanical properties requires to perform mechanical tests according to different loading situations, as different loading directions. Because of the typical functionality of colon structures, the tissues mechanics is investigated by tensile tests, which are performed on taenia coli and haustra specimens from fresh pig colons. Accounting for the histological investigation and the results from the mechanical tests, a specific hyperelastic framework is provided within the theory of fiber-reinforced composite materials. Preliminary analytical formulations are defined to identify the constitutive parameters by the inverse analysis of the experimental tests. Finite element models of the specimens are developed accounting for the actual configuration of the colon structures to verify the quality of the results. The good agreement between experimental and numerical model results suggests the reliability of the constitutive formulations and parameters. Finally, the developed constitutive analysis makes it possible to identify the mechanical behavior and properties of the different colonic tissues. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1243-1254, 2014.