TITLE:
Effect of deformation rate on the mechanical properties of arteries
AUTHORS:
Jorge O. Virues Delgadillo, Sebastien Delorme, Vincent Mora, Robert DiRaddo, Savvas G. Hatzikiriakos
KEYWORDS:
Mechanical Properties; Artery; Uniaxial & Biaxial Testing; Deformation Rate; Viscoelasticity; Constitutive Model
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.3 No.2,
March
1,
2010
ABSTRACT: Pig aorta samples were tested uniaxially and equi- biaxially at deformation rates from 10 to 200 %/s. Under uniaxial and biaxial testing, loading forces were reduced up to 20% when the deformation rate was increased from 10 to 200 %/s, which is the opp- osite to the behaviour seen in other biological tissues. A rate-dependent isotropic hyperelastic constitutive equation, derived from the Mooney-Rivlin model, was fitted to the experimental results (e.g. aorta specimens) using an inverse finite element technique. In the proposed model, one of the material par- ameters is a linear function of the deformation rate. The inverse relationship between stiffness and defo- rmation rate raises doubts on the hypothesized rel- ationship between intramural stress, arterial injury, and restenosis.