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results depend on parameter sweep order?
Posted 29.04.2014, 03:10 GMT-4 Studies & Solvers, Structural Mechanics Version 4.4 0 Replies
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Is it possible that in some cases the results of a structural mechanics simulation depends on the order in which a parametric sweep is done?
I am simulating the deformation of an object when it "hangs" from its support-points. The support can be tilted wrt. vertical about +/- 2 degrees.
So I am running a simulation where the body-force depends on the tilt-angle = range(-2,0.1,+2)
From this I would expect to get symmetric results, i.e. the -2 degrees tilt situation should look exactly symmetrical compared to the +2 degrees tilt situation.
However I seem to get "skewed" results and the -2 and +2 degrees tilt results do not look symmetrical.
What I think is happening is that comsol solves the FEA problem for one case, the first parameter value of -2 degrees, and then all other solutions are small (linear?) modifications to this original solution.
I have yet to try what happens if I run the same simulation with tilt-angle = range(+2,-0.1,-2), or with individual parameter values of -2, 0, +2 degrees of tilt - allways erasing the previous solution between runs.
My model consists of a piece of glass, and the deformations are small, 1e-12 to 1e-10 displacements, so there might be some numerics that should be tuned also..
thanks,
Anders
Hello Anders Wallin
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