Analysis of High-Frequency Failures in Aortic Tissue at Varying Peel Rates
Aortic dissection is classified by a tear in the intima of the aorta which permits blood to push into, and delaminate, the media of the aorta. In order to investigate the mechanics of aortic dissection, peel testing has frequently been used to find the force required to delaminate the media of the aorta. Recent work has used peel tests to analyze “high-frequency failures,” which represent microstructural failures in the tissue. This study aims to investigate the impact peel rate has on high-frequency failures. 12 tissue samples from 2 porcine aortas were tested at peel rates of 3, 7.5, 15, and 30 mm/min. Empirical mode decomposition was used to isolate the high frequency failures from the peel test data. From these failures the tensile rise, displacement at failure initiation, interlamellar stiffness, tensile drop, displacement at delamination, and slope of failure were extracted. It was found that there was a significant difference at a 0.05 significance level in the displacement at failure initiation and displacement at delamination parameters. This indicates that peel rate does impact the high frequency failures. However, there was no ascending or descending relationship between high frequency failures and peel rates.