MSC NASTRAN for ABAQUS CAE

[nomi9]

Hello all,
I have a question regarding using MSC NASTRAN as a solver. I have prepared a model in Abaqus CAE. It is a complex model with different materials and it also has Cohesive Zone modeling defined using cohesive elements. Due to licensing issue, i can only use Abaqus for pre and post processing. And for this reason i am exploring to use NASTRAN as a solver. The model is non-linear and deals with debonding(CFRP-Metal).
Can you tell me if NASTRAN would be appropriate to use as a solver. If yes, which solver in NASTRAN can i use to get best and comparable results? And how do i convert my inp file to bdf file appropriate for NASTRAN. If NASTRAN would not be good to use as a solver, which other solver i can use?

With best regards

 

[FEA way]

And how do i convert my inp file to bdf file appropriate for NASTRAN.

I won't help you with Nastran because I don't use it but Abaqus has a built-in converter: abaqus tonastran command. Only selected input deck cards can be translated though. Check the documentation chapter "Translating an Abaqus Input File to a Partial Nastran Bulk Data Text File".

 

[SWComposites]

you will need to use Nastran Sol400 for this nonlinear analysis. However, I strongly recommend using Abaqus.

 

[ThomasH]

One possibility may be to import the model into a pre-processor that works with both Abaqus and MSC.Nastran. But I think that will require a lot of testing to insure everything ultimately works as you intend it to work.

 

[dmapguru]

MSC Nastran SOL 400 has the possibility to model a cohesive zone (look for the CIFHEX entry) where you can define the proper dimensions of the bond (one of the element dimensions may be extremely small compared with the other two). The PCOHE entry is used to define the element properties for the onset and progression of delamination with the MCOHE material entry providing the material model. As a more rudimentary alternative, it is also possible to define what is affectionately called breaking glue. The contact definition allows a limit force or stress (user choice) at which a contact surface that is currently bonded will spearate, breaking the glue, from which point the contact behaves as any other contact that may touch or separate (i.e. no glue).

To assist with getting your inp file to a bdf file, look in the MSC Nastran installation directory for the program abq2nas. This will appear in the Win64i8 directory on Windows or the linux64i8 directory in Linux. This translator does a good job of the most common artefacts of a model, but you may find some of the more esoteric aspects are either not supported, and have to be added by hand, or occassionally are not to your liking; an example might be the way a constraint equation is represented. If you have Hexagon product licenses, you could use Patran or Apex to assist in the final touches of setting up the model.

DG