Figure 10.

Evolving transmural circumferential (bold curves) and axial (light) Cauchy stresses for the loaded in vivo configuration (panel a) and the excised, intact configuration (i.e., residual stresses; panel b) at indicated actual ages. All results for β_c = 0.2. The sharp discontinuity marks the interface between the medial and adventitial layers. As a result of the lack of axially-oriented fibers of collagen in the media, the in vivo circumferential Cauchy stresses are higher than the axial stresses. The adventitia, lacking both elastin and active smooth muscle, bears substantially lower equibiaxial stresses. As the artery ages, in vivo axial Cauchy stresses decrease, particularly within the media. Also, stress gradients within the media diminish in the unloaded configuration.