THE ANEURISMAL ABDOMINAL AORTA WALL MECHANICAL RESISTANCE LOSS AND COLLAGEN FIBRE PATHOLOGICAL REORIENTATION. A NUMERICAL STUDY
 
Bouteraa Samira, Bouaricha Amor, Zemouri Zahia, Berkani Mahièddine (DOI: 10.24874/jsscm.2023.17.01.08)
 
Abstract
 
The biomechanical properties’ changes of the abdominal aortic aneurysms’ (AAA) walls are closely related to the pathological degeneration of the smooth muscle cells and the main fibrous components (collagen and elastin). In this study, the passive mechanical response of the aneurysmal aortic wall is computationally investigated as a function of the dispersion and orientation of collagen. So, to better understand how the ultimate resistance of the diseased wall varies, several numerical simulations on models of AAA specimens have been performed, using the Gasser-Ogden-Holzapfel anisotropic hyperplastic constitutive model where the dispersion and orientation parameters are explicitly introduced. The simulations were carried out for a variation of the average orientation of the collagen from 0° to 90° with a dispersion that varies from 0 (orthotropic case) to 1/3 (isotropic case). The results of the numerical simulations show that an increase in the dispersion and the angle of orientation in the aneurysm leads to a decrease in the circumferential resistance of the diseased artery. Such results can help to better understand the negative effects of the disease on the arterial wall and to target the necessary therapy.