I don't know if Abaqus readily provides the energy release rate. You can plot the reaction force over displacement and use the integral to get increments of the fracture energy. The crack propagation at each time step can be extracted using the Abaqus variable CSDMG. The rest would be numerics.

I added two pictures to give you further hints, which I took from the dissertation of Michael Schober (https://publikationen.bibliothek.kit.edu/1000100455).

Hi Nicolas,

Nicolas Christ Thank you very much for the answering!

i have read some pages of the attached dissertation and realize that the formula and the picture mentioned are actually one method to calculate "critical energy release rate", however the "strain energy release rate" (also the mode I fracture toughness G1c) can be calculated using data reduction method according to ASTM D 5528-13.

I would like to know what is the relationship between Critical energy release rate and Strain energy release rate G1c? Are this two the same when under pure Mode1 test?

Best regards

Yang

I am sorry, but I am no expert in fracture mechanics. To my understanding the strain energy release rate and the critical energy release rate are equivalent for the case of linear fracture mechancis. Check the book Fracture Mechanics (or Bruchmechanik in German) by Gross and Seelig for this matter. Chapter 4.6.2 has some words about this and also a reference to the DCB experiment. Maybe also check Griffith's criterion (see this https://web.mit.edu/course/3/3.11/www/modules/frac.pdf). I hope this helps a bit.

Thank you again for the answer! Nicolas Christ

In my opinion, the critical energy release rate G1c is a specific strain energy release rate. "critical" means G1c is the strain energy release rate only calculated with standard BCD test (flat beam, the upper and lower beams are exactly the same). So they are the same in a flat beam DCB test as i think.

And the method you offered is under the assumption of linear-elastic fracture mechanics(LEFM) which actually works well in the DCB simulation. I tried to calculate the R-curve and find it is in good consistancy with the experiment. Thanks!

furthermore i find another method that can also calculate energy release rate in Abaqus: using the energy balance. The formula is shown below. and the "work of external force" and "stored strain energy" can bu output in ODB history output.

I hope my suggestion is useful, if anyone has better idea please also write here!

I‘m glad that you found a way to progress with your problem. Thanks for the additional info that you provide to further help people with similar struggles :)