Residual stress is very important for the study of cardiovascular-relevant issues, such as assessing the vulnerability of atherosclerosis and aneurysm. In this paper, the circumferential residual stress of porcine aorta was characterized by combining ex vivo experiments with numerical studies. In the experiments, porcine aortic rings were prepared and cut open, and the cross sections of the opened aortic rings were extracted to construct finite element models. The 5-parameter Mooney–Rivlin model was chosen to describe the tensile mechanical behavior of the aorta. In numerical studies, based on the finite element models and hyperelastic material model, a pulling-back displacement was applied to reclose the models of the opened aortic rings, and the equivalent circumferential residual stress to the pre-opened aorta was analyzed. The results showed that the circumferential residual stress of the aorta generally decreased from the proximal to the distal ends, and the residual stresses of the aortic rings close to the distal end did not show a great difference. This work provides an improved understanding of the residual stress distribution in aorta and may be used as a more realistic initial condition for future stress analysis of the arterial tissue.

残余应力对于研究与心血管有关的问题非常重要，例如评估动脉粥样硬化和动脉瘤的脆弱性。本文通过结合体外实验和数值研究来表征猪主动脉的周向残余应力。在实验中，准备猪的主动脉环并切开，并提取打开的主动脉环的横截面以构建有限元模型。选择5参数的Mooney–Rivlin模型来描述主动脉的拉伸力学行为。在数值研究中，基于有限元模型和超弹性材料模型，应用回拉位移重新封闭打开的主动脉环模型，并分析了预打开主动脉的等效周向残余应力。结果表明，主动脉的周向残余应力通常从近端到远端减小，而靠近远端的主动脉环的残余应力没有显示出很大的差异。这项工作可以更好地了解主动脉中的残余应力分布，并且可以用作将来对动脉组织进行应力分析的更现实的初始条件。