How do you FEA structural foam?

[Glenn9]

We are analyzing the panels used for an in ground swimming pool. They are roughly 4 feet by 6 feet with typical wall and rib thickness of 3/8 inch. Material is polystyrene - structural foam. ANSYS can handle the analysis as a Blatz-Ko or Ogden Non-Linear analysis, but the software requires inputs such as mu, alpha, beta for each temperature and each order of the polynomial. DOES ANYONE KNOW WHERE TO OBTAIN THESE CONSTANTS? If you have any real hands on experience in analyzing structural foam, then we are interested in talking to you. Thank you.

 

[caviac]

mu,alpha and beta are known as c1,c2 and c3 constant for the foam law in others software also.
You need to have the laws by tests an d calculation or just tests...it costs money of course
ANSYS is not the best for that but what do you want ot do with the foam ?

caviac

 

[jorgenb]

The Ogden model can be fitted rather well to the equilibrium response of PS structural foam. You need to experimentally test the foam using uniaxial compression and confined compression, perhaps even simple shear. Then you need to find the required material parameters from the experimental data. Both testing and finding the material parameters is rather easy, if you have the right equipment & tools.

Best of luck,
Jorgen

(polymerFEM.com)
Information about advanced FEM of polymers.