surfaces in 3D

[cheng]

I'm trying to simulate a tensile test on a dogbone specimen.
I have some questions:
1- how can I calculate the areas (or the integral of a given variable over an area) along the x-z plane? I can see the grid, as in the script attached, but I cannot identify the regions. For instance, I need to calculate the deformed area at the centre of the specimen and the force needed to deform the dogbone.
2- I'm running the script with flexpde6 student version. Despite the fact that the deformation is symmetric with respect to the plane at x=0, the areas appear slighlty twisted around the y axis. Is this just a problem of solution accuracy.
Thanks for the attention and for the great software

[moderator]

1 - The simplest way would be to create a FEATURE across the domain (i.e. y=0). This would create an additional vertical surface face in 3D. Then you can request a SUMMARY report of the surface integral of your variable. See the attached script where I have done this. Note that this would have to be done differently if your integrand was the normal component of a vector (since the normals on each side of the cut plane would cancel each other out).

2 - Yes, apparently this is an artifact of not having enough cells. The professional version regrids to about 12000 cells and the plot is symmetric.