Inostroza Matías, Utrera Andrés, García-Herrera Claudio M, Rivera Eugenio, Celentano Diego J, Herrera Emilio A
Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Santiago, Chile.
Departamento de Ingeniería Mecánica y Metalúrgica, Pontificia Universidad Católica de Chile, Santiago, Chile.
Front Bioeng Biotechnol. 2023 Aug 22;11:1233939. doi: 10.3389/fbioe.2023.1233939. eCollection 2023.
This work consists of analyzing the impact of geometrical features (thickness and curvature) on the estimation of circumferential residual stresses in arteries. For this purpose, a specific sample of lamb abdominal artery is chosen for analysis and, through computational tools based on Python libraries, the stress-free geometry is captured after the ring opening test. Numerical simulations are then used to reconstruct the sample in order to estimate the circumferential residual stresses. Then, four stress-free geometry models are analyzed: an ideal geometry, i.e., constant curvature and thickness; a constant curvature and variable thickness geometry; a variable curvature and constant thickness geometry; and a variable curvature and thickness geometry. The numerical results show that models perform well from a geometric point of view, where the most different feature was the closed outer perimeter that differs about 14% from the closed real sample. As far as residual stress is concerned, differences up to 198% were found in more realistic models taking a constant curvature and thickness model as reference. Thus, the analysis of a realistic geometry with highly variable curvature and thickness can introduce, compared to an idealized geometry, significant differences in the estimation of residual stresses. This could indicate that the characterization of arterial residual stresses is not sufficient when considering only the opening angle and, therefore, it is also necessary to incorporate more geometrical variables.
这项工作包括分析几何特征（厚度和曲率）对动脉周向残余应力估计的影响。为此，选择了一个特定的羊腹主动脉样本进行分析，并通过基于Python库的计算工具，在开环试验后获取无应力几何形状。然后使用数值模拟来重建样本，以估计周向残余应力。接着，分析了四种无应力几何模型：理想几何形状，即曲率和厚度恒定；曲率恒定但厚度可变的几何形状；曲率可变但厚度恒定的几何形状；以及曲率和厚度均可变的几何形状。数值结果表明，从几何角度来看，这些模型表现良好，其中最不同的特征是封闭外周，它与真实封闭样本相差约14%。就残余应力而言，以曲率和厚度恒定的模型为参考，在更现实的模型中发现差异高达198%。因此，与理想化几何形状相比，对曲率和厚度高度可变的现实几何形状进行分析，可能会在残余应力估计中引入显著差异。这可能表明，仅考虑开口角度时，动脉残余应力的表征是不够的，因此还需要纳入更多几何变量。
