Composite failure analysis using MD Nastran 2010

[dimiZarah]

Hello there,

I am using Patran 2010 and MD Nastran 2010 to simulate a quasistatic tensile test of a multidirectional GFRP configuration. Firstly, I selected
to perform the simulation using shell elements. Following some tutorials found in internet, I managed to build up the model (Hashin criterion, progressive failure etc).
I selected the implicit non-linear SOL 400 as solution type and the incremetal type is adaptive. The simulation seems to run ( I compare each ply's stresses/strains to analytical formulation).
However the total damage for progressive failure, the fibre and matrix damage for progressive failure is zero.

Does anybody have an idea why this happens?

 

[ZeroExperience]

There are millions of causes for your issues. I would do the following,

1) Redo the tutorial, make sure you get the same answers as in the tutorial.
2) Analyze a laminate that consists of only one ply and ensure you can at least set up one ply.
3) Next add another ply, run it, if it works fine, add another ply and repeat. Take small steps and troubleshoot at each step if needed. NEVER GO ALL OUT IN THE BEGINNING. ALWAYS START SMALL!

 

[dimiZarah]

ZeroExperience thank you for your response.

Actually, I used extensively ANSYS to implement progressive failure analysis in an element basis (and not ply-to-ply as NASTRAN performs) compiling the code with APDL.
I have done the steps you recommended and everything works except the index for the total progressive failure etc. Somehow a module of NASTRAN or PATRAN is deactivated or activated which constrains the failure's representations. The tutorials are based on PATRAN 2012 ( I use PATRAN 2010) and i was wondering if that causes any conflict...

So my question has to do more with the practical implementation and usage of PATRAN- MD NASTRAN and less with the background of the composite structures' failure analysis...