Model Theory

The Bergstrom-Boyce (BB) model is one of my favorite material models, partly because it was the first advanced material model that I developed, and partly because it works really well for predicting the non-linear viscoelastic response of rubbers despite being a simple model.

The following figure shows a rheological representation of the BB-model.

The model consists of two parallel networks: Network A gives the equilibrium response of the material, and network B gives the viscoelastic contribution to the stress. This model structure is deceivingly similar to the rheological representation of linear viscoelasticity (LVE) theory. The BB-model, however, is significantly different than LVE. For example...