Figure 5.

Permanent deformation in a blood vessel subjected to repetitive loading. The blood vessel did not recover its original shape after being subjected to three cycles of 10% and three cycles of 20% compressive strain. The arrowheads on the microscope images indicate two brain cells and two endothelial cells that could still be identified after repeatedly leaving and re-entering the field of view (FOV). The displacements of those cells during the three loading cycles with maximum strain ${\epsilon }_{\mathit{max}}=20$% are shown in the left subfigure.