Balzani D, Schröder J, Gross D
Institute of Mechanics (AG 4), Department of Mechanics, Technical University of Darmstadt, Hochschulstr. 1, 64289 Darmstadt, Germany.
Acta Biomater. 2006 Nov;2(6):609-18. doi: 10.1016/j.actbio.2006.06.005. Epub 2006 Sep 1.
When a balloon-angioplasty is performed, the arterial wall is overstretched and thereby damaged, which leads to a stiffness reduction in the arterial layers. An anisotropic damage model able to reflect the main damage mechanisms in overstretched arterial walls is used in combination with a polyconvex hyperelastic stored energy function. Furthermore, a method for the incorporation of residual stresses present in the wall of unloaded configurations is applied. The energy describes the anisotropic hyperelastic behavior of arteries under physiological conditions. Due to the assumption that the rupture of cross-bridges between collageneous micro-fibrils is responsible for the damage inside arterial walls, the damage function is applied to that part of the energy only which is associated to the fiber elasticity. For the incorporation of the residual stresses into the simulation, we apply a method which consists of two simulation steps. Finally, a numerical simulation of the overstretching of a simplified atherosclerotic artery is performed taking into account residual stresses.
当进行球囊血管成形术时，动脉壁会过度伸展从而受损，这会导致动脉各层的僵硬度降低。一种能够反映过度伸展动脉壁主要损伤机制的各向异性损伤模型与多凸超弹性储能函数结合使用。此外，还应用了一种纳入未加载构型壁中存在的残余应力的方法。该能量描述了动脉在生理条件下的各向异性超弹性行为。由于假设胶原微纤维之间的交联断裂是动脉壁内损伤的原因，损伤函数仅应用于与纤维弹性相关的那部分能量。为了将残余应力纳入模拟，我们应用了一种由两个模拟步骤组成的方法。最后，在考虑残余应力的情况下，对简化的动脉粥样硬化动脉的过度伸展进行了数值模拟。
