How to model necking (damage)

[msuhairil]

Hi,

I am modelling tensile dog bone specimen. I manage to simulate until before it neck..After that, i dont know..i read through the manual that we have to set damage model..for instance using Damage for ductile materials..However, the problems arise..how to measure stress triaxiallity,fracture strain and strain rate?..please anybody help me. The material is steel. Or maybe other suggestions?

 

[mrgoldthorpe]

Hi,

I think perhaps you need to read around the subject a little.

In the meantime I attach an ABAQUS input file which does what you want and attempts to simulate the Round Robin cited in the file using *POROUS PLASTICITY.

 

[msuhairil]

thanks mrgoldthorpe for the files..unfortunately i cannot open it *Parameterized input files can not yet be imported into Abaqus/CAE*..those model using porous plasticity...I look into manual from abaqus..just excercise..but could not get idea how to get stress triaxiallity,fracture strain and strain rate (damage for ductile materials)..or any parameters using different damage model.. There must be some procedures to be implemented before we get these parameters right?..

 

[mrgoldthorpe]

If you run ABAQUS PRE you'll get a .pes (if memory serves me) file in which all the parameters are resolved. You can run that in CAE.

I'm not sure what you are asking in the rest of your question, but you generally need to tune your model against experiments in order to obtain the appropriate parameters of the damage model. Read some of the background journal papers.

 

[msuhairil]

Hi mrgoldthorpe ,
from the input file you gave me (eventhough i could not open it), i focus on the material properties that u input..how you obtain (from literature) q1,q2,q3 for ductile porosity ??..is there any step to get the value?..and does this simulation include damage analysis i mean until fracture? (including necking)..im so sorry because i still dont understand your statement [highlight #FCE94F]If you run ABAQUS PRE you'll get a .pes (if memory serves me) file in which all the parameters are resolved. You can run that in CAE.[/highlight] ..ABAQUS PRE?