[Solved] Modified Unloading Predictions using the BB-model

This file describes one method that can be used to modify the Bergstrom-Boyce (BB) model. It has been shown that some elastomers have weaker strain-rate dependence during unloading than during loading, this experimentally observed characteristic is not captured in the original BB-model. This unpublished report discusses one way to phenomenologically extend and improve the predictions of the BB-model for these elastomeric materials.