Abaqus {car shock absorber (polyurethane foam)}

Good day,

I'm trying to numerically simulate the compression of a polyurethane foam shock absorber for car.

I use ABACUS/Explicit

The constants for the equation of state were obtained from experimental data for compression, at a "characteristic" (small) compression rate using the MCalibration program.

While resolving, an error message was received:

The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element.

One of the possible causes of the error is the incorrect calculation of the constants for the polyurethane foam equation of state.

*** using the "standard" equation, which is in ABAQUS

I am ready to send the model and experimental data to anyone who has the desire and opportunity to devote time to this task.