INTEGRATION OF VISCOELASTIC MATHEMATICAL MODEL TO EXPERIMENTAL DATA TO GENERATE MATERIAL PROPERTY DATA FOR FINITE ELEMENT MODEL

METHODS: A quasi-linear viscoelastic (QLV) computational model was proposed by Fung in 1972 that exhibited the time-history dependence of linear viscoelastic models along with nonlinear elasticity. The model addresses the time-dependent behavior of viscoelastic materials using multiple linear approximations. Abramowitch and Woo (2004) expanded on Fung's QLV model, proposing a modified experimental protocol to address experimental limitations of a step change in strain. Following stress-relaxation tests, which involve subjecting materials to constant strain and recording the stress response, constants defining the material's viscoelasticity can be determined by applying the Abramowitch & Woo QLV model to the experimental data. These constants are then used as material property inputs into the FEM to ensure the most realistic reaction to virtual insults. RESULTS: Our laboratory has performed experimental viscoelastic characterization of cervical and lumbar spine soft tissues by utilizing the Abramowitch and Woo QLV model for implementation in a detailed statistically-based FEM.