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[Mumić <question688652@xxxxxxxxxxxxxxxxxxxxx>]

Question #688652 on Yade changed:
https://answers.launchpad.net/yade/+question/688652

    Status: Needs information => Open

Mumić gave more information on the question:
Hello and thanks for the reply!

> in what range?

Young was varied between 20 and 100 GPa and Poisson was varied between
0.05 and 0.9 for these inicial calibration tests

>if you are interested in elastic calibration, set parameters
influencing INELASTIC behavior such that the model remain elastic

I had tested some values on this parameter and as it did not influence
the obtained value, I kept it 1e-5, I was wrong.

But now ran a simulation using 1e-1 and 1e0, the value of Poisson
changed from 0.187 to ≃ 0.258 when moving epsCrackOnset from 1e-5 to
1e-1 but didn't change between the last two (1e-1 to 1e0), so I guess in
this case it's way safer to assume this parameter is not influencing
anymore, but yet the micro poisson didn't change much

Is the range of the other parameters I'm using way off to have an actual
effect?

>as you can see, by changing the poisson value, the obtained macro value DID NOT remain the same.
>Please provide what a why did you expect

The element position was obtained for any timestep in which the material
behavior is within the elastic domain and then compared with the initial
position in order to find the deformation in that region, then, based on
the formula nu = (-0.5(ex+ey))/ez, Poisson modulus was computed.

Regarding the "the value did remain the same",  that graph was computed
on a single timestep, if I take the average, are equal up to 4 decimal
values. I agree the shown method was a poor one, hence I moved to
obtaining a linear regress of the computed strains and the results are
now more reliable than the former one.

In this new evaluation, the value for epsCrackOnset used was 1e-1, Micro
Young 50e9 and Micro Poisson 0.2 or 0.4. The results are displayed
below:

Micro Poisson = 0.2 ⇒ https://user-images.githubusercontent.com/19715340/74276747-0c94d380-4cf5-11ea-8a54-c9fcc8ce6e6e.png
Micro Poisson = 0.4 ⇒ https://user-images.githubusercontent.com/19715340/74276830-3b12ae80-4cf5-11ea-9acd-23363186a653.png

What I expected was for the values to change based on the input young
and poisson but the value I'm measuring so far is kind of static when
varying the elastic parameters. The reason of what I'm looking for is
that Macro Young is directly related to the Micro Young whereas Macro
Poisson is a function of Micro Young and Micro Poisson.

Best regards!

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