Fig. 3.

Change in longitudinal (z, red line) and circumferential (θ, blue line) damage initiation stretches (A) and Cauchy stresses (B) with age. The dashed gray lines represent the 5^th and 95^th percentiles for each direction. Damage initiation stretches can be described by linear functions −0.0081*age+1.7656 (R² =0.73, longitudinal) and −0.0075*age+1.7253 (R² =0.71, circumferential). Damage initiation stresses can be described by linear functions −2.82*age+282 (R² =0.29, longitudinal) and −2.09*age+235 (R² =0.21, circumferential).