Polyurethane Foam Modeling

[mhaaser]

I am trying to model a sandwich panel with a polyurethane foam using ANSYS. I am unfamiliar with the modeling of foam and was hoping for a recommendation on what types of tests would give me the data I need and also what material models would be the best to use. The type of foam is ELASTOPOR P 15390R Resin/ELASTOPOR P 1001U Isocyanate. It is a two component polymeric MDI based system utilizing water and HFC-245fa as blowing agents. Any information at all would be appreciated.

[Jorgen]

Foams are typically characterized by a combination of uniaxial tension, uniaxial compression, and confined compression experiments. As an alternative to the uniaxial experiments, you can also use shear experiments. Note that for foams it is important to perform some kind of confined compression or triaxial compression experiments.

The best choice of material model will depend on the strain levels and degree of accuracy that you need from your simulations. What strain levels do you need to simulate, and what temperature and strain histories are you interested in?

Jorgen

[mhaaser]

The sandwich panels are panels for air handlers. The amount of strain is fairly small. In flexure tests of the panels so far it is less than .5" for a 96" long panel. Temperature is not too important for this application. The temperature the foam will experience does not vary too far from room temperature.

[Jorgen]

It sounds like you are mostly interested in small strains, and that the deformation state is mostly tension, compression, and perhaps some shear.

Based on that I would start by performing exactly those experiments: uniaxial tension, uniaxial compression, and simple shear. I would then initially attempt to fit a hyperfoam model (*Hyperfoam in ABAQUS) to the data. Note, there are many models that should be able to capture the experimental data for your material and the specified loading histories.