Date of Award

Spring 1-1-2011

Document Type


Degree Name

Master of Science (MS)


Mechanical Engineering

First Advisor

J. Hang Qi

Second Advisor

Wei Tan

Third Advisor

Mark Rentschler


This work presents a characterization of the influence of viscoelasticity on the mechanical behavior of bovine pulmonary arteries. Stress relaxation tests are used to determine the time dependent response of bovine pulmonary tissue. Fitting this data to a modified standard linear solid model, allows a total of five independent time constants are attained, each of which describe individual time scales on which the medium has a viscoelastic response to an applied strain. These time constants are applied to an analytical model through the Boltzmann integral in order to describe the stress response to a prescribed loading strain. These results were also modeled using finite element simulations in order to verify the time dependent response. It was found that although viscoelasticity is a necessary consideration, depending on the loading conditions, it may in some cases be either neglected or simplified.