Hi everyone.

I'm deepening into ductil damage model. I'd like to share a methodology about it. I'm curious about characteristic length of the elements. There is some notes in the documentation (based on geometry mean, line through the element, in the VUCHARLENGTH subroutine example assess the characteristic length as the maximum diagonal of the element), but it doesn't explain well how is exactly calculated (at least I didn't find it). Also, I'd like to know which length is taken for:

a) The onset of damage: 

- Is the characteristic length of the element at the begining of the analysis or the characteristic length at the onset of damage?

b) During damage evolution:

- For the calculation of equivalent plastic displacements (up = L*ep), Is L constant and one of the previous characteristic lengths or is updated during the analysis based on the plastic strain increments?

Thank you in advance

Abaqus ​​​​​​​