Hi,
I am beginner in abaqus and I want to write a VUMAT for VIB method to simulate fracture, while writing VUMAT i encountered following problems
1) For 2D plane stress problem how to calculate strainInc(*,3). It is increment for that step or value of strain till that step?
2) What is effect of that defination on answer I am getting?
3) I am comparing my code of elastic VUMAT with inbuilt abaqus results however results are quite differant, then I observed as abaqus inbuilt is using logarithmic strains and i was using engineering strains. then i calculated strains for Vumat like
e1=0.5*(C-I)
then
e(*,*)=ln(1+e1(*,*))
and used this e in my relation to get stressNew answers are matching
so i want to know is it correct way to calculat strains?
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