Anisotropic material laws in OpenRadioss

[JAWilliams123]

Hello Everyone,

Happy New Year!!

Are any of the Radioss Aniostropic material laws with damage available in OpenRadioss? In particular, I would like to use use MLaws 28, 50 or 68. The aim is to model failure in bamboo. Any recommendations for available material models in OpenRadioss will also be appreciated.

Many thanks,
JWilliams

[MarianBulla]

Hi @JAWilliams123,
and happy new year to you, too :-)

Yes, there are many material models, which can cover the anisotropic behavior in OpenRadioss. Some of them contain damage and failure models. If not, you can add an external failure criterion in addition to your material model using /FAIL/xxxx/yyy (where "xxx" is the failure law and "yyy" is the ID of your material, where the failure model will be added to.

Anyway, LAW50 is a good choice. It is a honeycomb material with the possibility to model the viscosity (strain-rate) effect. LAW28 is a simpler version of the honeycomb model. LAW68 is much more advanced.

For these kind of materials, I used LAW25, in the past. It works with 3D-Elements, as well.
In addition to this material, you can add failure criteria, e.g. /FAIL/HASHIN.

For more details, please review the documentation/manual page: https://help.altair.com/hwsolvers/rad/topics/solvers/rad/materials_starter_overview_r.htm

Hopt helps you ?

Thanks and best regards,
Marian

[JAWilliams123]

Hello @MarianBulla,

Yes, your response is very helpful. Thanks again for the usual clear and detailed response. :)

Best wishes,
JW

[JAWilliams123]

Hello @MarianBulla,

I was not sure if I should open a new discussion on this but can a stress-strain curve in only one direction be used as input for my sample. e.g. I have been given E11, E22, E33, G12, G13 and G23 for the sample along with the displacement-force output for the transverse direction (E22) which I have already converted to a trues stress-total strain curve. Using LAW25 as suggested in your post, how can this curve data be used?

Many thanks,
JW

[MarianBulla]

Hello @JAWilliams123,
yes, LAW25 would work, but it is a bit more difficult to fit it to a given stress-strain curve.

Maybe you can check out other material laws.

Or maybe LAW93 would fit best for your application ?

For more info, please review the documentation: https://help.altair.com/hwsolvers/rad/topics/solvers/rad/materials_starter_overview_r.htm

Hope it helps you ?

Thanks and best
Marian