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How to model a compressible foam with SW-simulation.

Question asked by Joseph Eimer on Mar 21, 2012
Latest reply on May 1, 2012 by Jerry Steiger



I'm trying to model a foam disk supported by an alluminum ring with atmosphere on one side and vacuum on the other (bonded interfaces).  The atmosphere will naturally distort the foam into a complicated diflected shape.  Some material characteristics of the foam are presented here: 


I have several questions on how to properly model this system.


1) What is the appropriate non-linear material model to use?  I believe the Blatz-Ko model assumes too flimsy of a materail to be useful here.


2) The data sheet linked to above lists both compressive stess-strain and tensile strength.  How do you input this data into SW?  Do you assume a nonlinear model and use negative strains for compressive loads?


3) Since this situation involves cylidrical symmetry, I figured it would be more efficient to use a pie-slice of the structure with symmetry fixtures on the window and the support ring.  I would assume for a fixed mesh size, the result will be more acurate for a smaller slice of pie.  Is this correct? 


Thanks for any guidance!