Welcome to the forums. Please post in English or French.

You are not logged in.

#1 2021-04-04 17:54:33

pbiagini
Member
From: Prague
Registered: 2011-10-28
Posts: 25

Test with concrete law BETON_DOUBLE_DP

Hi Everyone,

I was testing the law BETON_DOUBLE_DP on a simple cube and got strange results when using parabolic law for the compression softening curve. The linear law works well.
Attached the working files with the two examples in the plots.
What am I doing wrong ???

Thanks ahead.

Best,
Paolo


Attachments:
CubeTest.zip, Size: 23.06 KiB, Downloads: 36

Offline

#2 2021-04-06 08:51:46

corra
Member
Registered: 2008-06-03
Posts: 152

Re: Test with concrete law BETON_DOUBLE_DP

Dear Paolo,

Yes it is indeed strange. Maybe you need to double check your boundary conditions? If you are applying a traction in x on the yzp plane, you should fix the yzn plane in x plus block any rigid motion (for instance, in addition n1 should be blocked in xyz and n4 should be blocked in z). All other BC may jeopardise the expected results.

Best regards,

Corrado

Offline

#3 2021-04-07 17:40:22

pbiagini
Member
From: Prague
Registered: 2011-10-28
Posts: 25

Re: Test with concrete law BETON_DOUBLE_DP

Hello Corrado,

thanks for your reply. The BC seem to be ok. In the same direction tension diagram works, as well as the compression one with linear representation of energy fracture.

Will try to play a bit more with it.

Best,
Paolo

Offline

#4 2021-05-09 00:19:44

MrSnail
Member
Registered: 2018-10-26
Posts: 35

Re: Test with concrete law BETON_DOUBLE_DP

I have seen that sudden jump with parabolic softening in my models too, cant explain why.
Moreover the Gc and Gf values.. I am not able to match any tests with them.
I stopped using Beton_Double_DP because of that.

Interesting enough, so far my best matches to confined test cubes are with using Mazars_GC with solid elements.
Although it is clearly stated that it should be used only for multifiber, but it predicts the failure with less error than any other materials I have tried. Also cant explain why.

I tried to predict s1 failure stresses with given lateral confinement based on Table 5 in the pdf below:
Strength behavior of plain cement concrete subjected to true-triaxial compression / Canadian Journal of civil engineering

Also attached the hdf if interested.


Attachments:
M20_Test1.hdf, Size: 813.08 KiB, Downloads: 10

Offline