The effect of the exclusion of the compressed fibers in the identification of material parameters from uniaxial tensile tests on two orthogonal strips is investigated. The micro-structurally based constitutive model with two dispersion parameters developed by Holzapfel and his colleagues is utilized in the study. A new exclusion method, based on the coefficient reflecting the percentage of stretched fibers, is proposed. The material parameters are identified by using experimental data from 30 uniaxial tensile tests (5 donors, 6 strips per donor) and a genetic algorithm code that is capable to find the optimal set of parameters. The contraction of the strip width computed by using the hyperelastic model with the identified material parameters is compared to the experimental data for two human aortas (one from literature and one experiment, specific for this study), in order to show the accuracy of the identified model. The complex behavior of the thickness deformation of the strip is also obtained and compared to the experimental data derived from in-plane measurements and the incompressibility condition. Results show that the in-plane fiber exclusion is appropriate for aortic material characterization with uniaxial tensile tests, reducing very significantly the computational cost. At the same time, thickness growth of strips during uniaxial tests is possible, depending on fiber dispersion and orientation.

研究了在两个正交条上单轴拉伸试验中排除压缩纤维对确定材料参数的影响。这项研究使用了由Holzapfel及其同事开发的具有两个分散参数的基于微结构的本构模型。提出了一种基于反映拉伸纤维百分比的系数的排除方法。通过使用来自30个单轴拉伸试验（5个施主，每个施主6条）的实验数据和能够找到最佳参数集的遗传算法代码来识别材料参数。将使用超弹性模型和确定的材料参数计算出的条带宽度的收缩率与两个人类主动脉的实验数据进行比较（一个来自文献，另一个是实验，特定于此研究），以显示所识别模型的准确性。还获得了带材厚度变形的复杂行为，并将其与从面内测量和不可压缩条件得出的实验数据进行了比较。结果表明，面内纤维排斥适用于通过单轴拉伸试验表征主动脉材料，从而显着降低了计算成本。同时，取决于纤维的色散和方向，单轴测试中条带的厚度可能会增加。结果表明，面内纤维排斥适用于通过单轴拉伸试验表征主动脉材料，从而显着降低了计算成本。同时，取决于纤维的色散和方向，单轴测试中条带的厚度可能会增加。结果表明，面内纤维排斥适用于通过单轴拉伸试验表征主动脉材料，从而显着降低了计算成本。同时，取决于纤维的色散和取向，单轴测试中条带的厚度可能会增加。