My primary research interests and recent activities have been in the areas of experimental test development and dynamic modeling. My recently completed Ph.D. research captures both of these elements as I developed an experimental method to capture the nonlinear frequency response of cushion materials and developed a distributed parameter model of a nonlinear, viscoelastic cushion material. The focus of the work was on the development of a model capable of capturing the small-strain behavior encountered in typical vehicle vibration applications. The model was developed from the constitutive relations of an axially loaded continuous rod. Verification of the model required an experimental technique sensitive to the nonlinear behavior of expanded polymer cushion materials. Since no industry agreed upon method capable of this exists, a technique was developed and used to capture the softening spring frequency response. This data then served to successfully validate the nonlinear, viscoelastic model developed both in the linear and nonlinear regions of material behavior.
