Delaminaiton modeling Radioss

Olof Lidström

Hi! For my thesis I am trying to simulate a sandwich plate with carbon fiber sheets, honeycomb core, inserts and Radioss Explicit. I try to use /FAIL/HASHIN condition for the carbon fiber. But I also would like the model to simulate delamination between the skins and the honeycomb core. 

Ideally I would like something similar to what can be used in Optistruct with MCOHE, where you can set a damage initiation criterion that takes normal stress "sigma_N" and shear stress "tau" in to account. And then I would like the delamination propagation to be "controlled" by energy dissipation "G". Why I would like to have something like "Sigma_N", "tau", "G" as parameters for this is because I would be able to test this in my sketchy own built testing machine.

So far I have not found or understood anything like this in Radioss, so I wonder if anyone have any tips of what material models/properties/criterions I could use to model this. Or if anyone have any idea how to test material properties for some of the other ways to model delamination between core and laminate in Radioss? Like Fail/Connect, /SNCONNECT or any of the other possibilities

Thank you very much in advance!

//Olof Lidström

(Sorry for a quite broad question, but I am a bit to lost to specify it more)

Guilherme_Brandao

Hello Olof,

I'm not a composite specialist, but in Radioss, some material laws are specific to connection materials. They can be found here: Connection Materials.
They are: Law54, 59, 83, 116, and 117. Law116 and 117 have an embedded failure model.

For failure models, we have /FAIL/CONNECT, /FAIL/SNCONNECT 
And one specific for delamination (interlaminar failure) /FAIL/LAD_DAMA

I don't have an exact answer for your application, but maybe it helps with your research.

Best regards,

Guilherme Brandão.