This work develops a methodology that generalizes the results of various experimental observations. Firstly, the particular material's viscoelastic constitutive properties are mathematically characterized by developing a constitutive relationship relating experimentally observed stress time histories to applied strain, and strain rate time histories. This constitutive relationship and a novel technique of "back integration" are employed to develop the material's creep compliance response. A Duhamel integral relationship is used to predict the material's actual strain time history given its observed stress-rate time history and creep compliance characteristic. This then allows casting the materials's loading history into its actual time dependent stress/strain space and determining if failure conditions have been exceeded. Both the theoretical development of this methodology and the effects of its application to the following two specific biological materials are presented: femoral cortical bone and mid-cervical anterior longitudinal ligament.
Abstract