Experimental Study on the Distribution of Circumferential Residual Strains in Aortic Arch

In order to quantify residual strains in aortic arch, curve length method and corresponding computerized measurement of vessel images are presented. White rabbits were taken as an example in the experiment. And cross-sectional configuration parameters of aortic arch, such as semi-major/semi-minor axis, wall thickness of arterial wall in the non-loaded state, and inner/outer curve length, wall thickness of arterial wall in the zero-stress state, were measured. Subsequently circumferential residual strains of aortic arch in the zero-stress state were calculated. As results of the experiment and calculation, axial distribution of residual strains in inner or outer walls along aortic arch is consistent well with the opening angle distribution, in which the variation magnitude is much smaller in the straight section than in the curved section. Simultaneously, not only the opening angle but also residual strains aren´t the function of circumferential coordinate θ, which means that circumferential distributions of the opening angle and residual strains are uniform. Furthermore, radial distribution of circumferential residual strains is nonlinear, and the radial gradient minimizes at the arch of aorta approximately.