  Arterial tissue consists of multiple structurally important constituents that
have individual material properties and associated stress-free configurations
that evolve over time. This gives rise to residual stresses contributing to the
homoeostatic state of stress in vivo as well as adaptations to perturbed loads,
disease or injury. The existence of residual stresses in an intact but
load-free excised arterial segment suggests compressive and tensile stresses,
respectively, in the inner and outer walls. Accordingly, an artery ring springs
open into a sector after a radial cut. The measurement of the opening angle is
commonly used to deduce the residual stresses, which are the stresses required
to close back the ring. The opening angle method provides an average estimate
of circumferential residual stresses but it gives no information on local
distributions through the thickness and along the axial direction. To address
this lack, a new method is proposed in this article to derive maps of residual
stresses using an approach based on the contour method. A piece of freshly
excised tissue is carefully cut into the specimen, and the local distribution
of residual strains and stresses is determined from whole-body digital image
correlation measurements using an inverse approach based on a finite element
model.
