Hi

In visualization module,you can use the "Query" tool to find the coordinates of crack-tip in each step of analysis and plot this x,y or z coordinates vs load of that step.

Hi Hos Zarrinzadeh

thanks for your response. That I understand you suggested to record the crack growth length manually in each step from visualization module. There is no automated way to request it in history output. Is that correct?

Another question for SIF, K. In a 2D XFEM analysis when I request SIF, K the ABAQUS says it can't be requested for 2D model. Is that SIF, K by XFEM could only be evaluated for 3D model?

Once again thanks for your help

Hi Dear friend

For your first question, as you said I did not find any history output for the mentioned problem.

For the second question, you CAN model 2D problems and extract SIFs.

I refer you to Dr. Pais' website

http://www.matthewpais.com

There you can see

1-Tutorials for 2D problems

2-Tutorials for 3D problems

3-MATLAB open source code for 2D plates

I found them very useful.

Hi Hos 

thanks for the link of Dr Matthew Pais. Obviously it is a good source for learning. I have reproduced the model for 2D static edge crack and tried to request SIF for XFEM crack from history output request. The message I receive 

'the following history output request applied to xfem cracks with crack domain that are not 3d solid'

again in 3D static edge crack SIF study of the Dr Pais website, a statement is there: Note that only 3D contour integrals are allowed within Abaqus, while 2D is used in MXFEM.

My conclusion is that may be 2D SIF study could be possible with Matlab but not in ABAQUS. Please correct me if I am wrong.

once again thanks

Hi Sikder

That seems right, I first thought you can not model X-FEM crack in 2D environment but your problem is deriving SIFs.

As you know abaqus just considers GROWING cracks in 2D models. On the other hand SIF calculation is implemented for stationary cracks, so you may not be able to derive SIF for such case.

Of course others tried to find alternative ways, take a look at this

http://imechanica.org/node/12695

while it seems the easiest way is to use Pais MXFEM code.

Hi Sikder,

Did you manage extracting your plot...I too would like to extract crack length vs. no of cycle.Please do let me know if you have found a way.

Regards,

Neelam

Hi Sikder,

Can you solve your first question regarding to plotting the crack growth length?. If yes, can you help me to give some guidance for that.

Many thanks.

many thanks mr Hossein Zarrinzadeh