ABAQUS contains an extensive library of material models, including models for metal plasticity and rubber elasticity.

The stress-strain data for the metal plasticity model must be defined in terms of true stress and true plastic strain. Nominal stress-strain data can be converted easily into true stress-strain data.

The metal plasticity model assumes nearly incompressible behavior once the material has yielded.

For efficiency ABAQUS/Explicit regularizes user-defined material curves by fitting them with curves composed of equally spaced points.

Polynomial, Ogden, Arruda-Boyce, van der Waals, Mooney-Rivlin, neo-Hookean, reduced polynomial, and Yeoh strain energy functions are available for rubber elasticity (hyperelasticity).

Hyperelasticity models allow the material coefficients to be determined directly from experimental test data. The test data must be specified as nominal stress and nominal strain values.

Stability warnings may indicate that a hyperelastic material model is unsuitable for the strain ranges you wish to analyze.

The default Poisson's ratio for hyperelastic materials in ABAQUS/Explicit is 0.475. Some analyses may require increasing Poisson's ratio to model incompressibility more accurately.

Generally, mass proportional damping is used to damp low-frequency oscillations, and stiffness proportional damping is used to damp high-frequency oscillations.

To avoid a dramatic drop in the stable time increment, the stiffness proportional damping factor, , should be less than or of the same order of magnitude as the initial stable time increment without damping.