The representative moiré pattern and contour diagram of the second principal stress under the open condition.

The red areas represent the high stress, whereas the blue areas are low stress. The stress concentration in the stentless valve (left) is evident at the leaflet belly and free margin by the support of the papillary flaps (regions labeled as “E” and “F”). The maximum second principal stress in the stented valve (right) is located at the center of leaflet belly (regions labeled as “I” and “H”).