Stress-controlled viscoelastic tensile response of bovine cornea.
The viscoelastic response of bovine corneas was characterized using in vitro load-controlled uniaxial tension experiments. Specifically, two types of tests were employed: cycled ramp tests over a range of loading rates and creep tests over a range of hold stresses. Multiple replicates of each were used to quantify natural variability as well as mean trends. A preconditioning protocol was used to obtain a unique reference state before testing and to overcome the effects of non-physiological loading. A quasi-linear viscoelastic model incorporating a representation of the microstructure of the cornea was compared to the experimental results. For low stresses and moderate durations this model compares favorably, but overall the material displays non-linearities that cannot be represented within the quasi-linear framework.
Boyce
B L
BL
Microsystems Materials Department, Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87123, USA. blboyce@sandia.gov
Jones
R E
RE
Nguyen
T D
TD
Grazier
J M
JM
D000818:Animals; D002417:Cattle; D003315:Cornea / Q000502:physiology*; D004548:Elasticity; D013314:Stress, Mechanical; D013718:Tensile Strength; D014783:Viscosity