I am an engineering student working on modeling a hyper-elastic tube in ABAQUS 6.7. The goal of the research is to increase the axial compliance of the tube by patterning holes in it. I have been matching simple physical stress/strain tests with ABAQUS simulations, by converting the the 'true' stress (abaqus results) into the engineering stress (benchmark testing). This was no problem for the solid tube, (assuming constant volume, incompressibility) the experimental, and and simulated stress/strain curves matched right up. (I entered uni-axial stress strain data to about 60% strain, and fit the material to an Ogden energy potential of order n=3 ).
The calculations of "true area" get more complicated as the hole patterns are modeled. I was curious of there was a way in the ABAQUS simulation to have it output the thickness/cross section area of the tube to get an exact area that the software is using to calculate true stress, so I could easily convert to engineering stress to verify the benchmark tests of more complicated patterns.
I noticed ABAQUS has a 'Profile' feature, but I do not really understand its purpose. I input the initial profile of the tube, and stretch it to 60% strain I could not figure out how to make it display the profile at each step in the static analysis. If anyone knows how to do this, or another easy way to convert the true stress given by ABAQUS into engineering stress for a simple straight tube (w/ cut outs on the walls) it would be much appreciated, as I have no prior FEM experience.
Thanks A Lot,