Hello Dr. Bergstrom,
For linear viscoelastic materials, we can measure their dynamic moduli and tan delta from forced oscillation tests and they should be strain-independent. Meanwhile, for nonlinear viscoelastic materials/composites, such as filled elastomers, we can still obtain the equivalent dynamic moduli and tan delta (I think rigorously speaking these terms are valid only in linear viscoelasticity) from forced oscillation tests, however they are strain-dependent (or stress-dependent). Since B-B model can well capture the large-strain and time-dependent stiffness and hysteresis of elastomers/filled elastomers, suppose we have all necessary material parameters for B-B model, how do we predict the dynamic moduli and tan delta of such a material? Or are there any references related with this topic? Thank you!