I could use some advise on inputting damping or hysteresis into abaqus. I am interested in damping with reference to elastomers. For example, damping to me is tan delta or the viscous (loss) modulus divided by the elastic (storgage) modulus. In abaqus I have experence with the Neo Hooke material model which uses shear modulus and bulk modulus but this results in a linear load vs deflection which shows no damping or hysteresis. I want to be able to produce a load vs deflection curve which has damping or hysteresis. For example, I know the elastomers I am trying to model should have a tan delta of 0.2 (low damping) to 0.8 (high damping) depending on if I am trying to model a low or high damped material. Is there a way to input tan delta into a abaqus material model? All my research says that I need viscous (loss) and elastic (storgage) modulus data as a function of frequency. I have the data, but my results do not correlate with actual test runs. Besides, I am having a hard time understanding why I need to convert my frequency data to dimensionless data by dividing by the long term or instantaneous modulus. Can someone explain how the long term or instantaneous modulus relate to the way I understand modulus? To me, modulus can be complex, elastic (storgage), viscous (loss), again with tan delta being the viscous (loss) divided by the elastic (storgage), and complex being the SQRT((elastic (storgage))^2+(viscous (loss))^2). The complex, elastic (storgage), and viscous (loss) modulus all change as a function of frequency. For example as frequency goes up, the tan delta could rise. Depending on the material and frequency range, this change in tan delta can be negelcted.

To recap: (1) Is there a way to input tan delta into a abaqus material model? (2) How does long term or instantaneous modulus relate to complex, viscous (loss), and elastic (storgage) modulus?

Thank you.