We are pleased to announce the format we have chosen for this year's CFRAC conference. This year's focus will be on dynamic cracking.

All CFRAC participants are invited to contribute this fracture benchmark organized by Julien Réthoré.

Authors are encouraged to present the results of their simulations in the benchmark session, which supplements the minisymposia.

Please note that this presentation is not counted when the policy of one presentation per registered participant is applied.

The results should be collected and sent to the organizer (julien.rethore@ec-nantes.fr)

We suggest that you try to simulate the results published in the article https://doi.org/10.46298/jtcam.10172, for which all the data are available here https://doi.org/10.5281/ZENODO.8256346.

You will find in these documents all the explanations on the tests carried out and all the results and raw data used to write this article.

This will give you the opportunity to compare your predictions with several tests (which are supposed to be identical but whose results differ because of the variability of the boundary conditions).

In particular, you will find:

• complete displacement fields measured by image correlation
• the boundary conditions to be imposed to make your simulations as realistic as possible

For your information, during a preliminary study, we found that for a realistic prediction of the first wave paths in the samples, a mass density of 1180 kg/m³, a Young's modulus of 6 GPa and a Poisson's ratio of 0.3 (in 2D plane deformation used). We also tried to simulate these tests using a phase field model with gc=1100J/m², lc=1 mm.

Julien Réthoré is available to answer any questions you may have, and hope that this benchmark will be of interest to you.

In the case where you are interested, you will have the opportunity to submit a second abstract into the Benchmark session and you will be invited to present and share your results in Porto.

Benchmark participants are asked to send their results by 31st May (ideally one week before).

If you cannot meet this first deadline, please let us know by email that you are planning a later submission, so that we have at least an idea about the expected number of benchmark presentations.

To make « anonymous » comparisons between participants’ results, you are asked to collect your results following these guidelines :

• using the provided data you should be able to simulate 4 different tests named TAF1, TAF2, T3DE, THOM. You can extract the exact boundary conditions on the left sample edge from the VTK files available on zenodo.
• for each test you simulate please send in 3 separate csv files named (%f_%d.csv, test name, index 1,2,3).
• in these files write the coordinates (in m) of the damaged/cracked points (what could be defined as a crack path using your model) with respect to the middle of the left sample edge at 3 times :
• for TAF1: instant 1: 60,0µs instant 2: 105 µs instant 3: end of your simulation
• for TAF2: instant 1: 63 µs instant 2: 108 µs instant 3: end of your simulation
• for T3DE: instant 1: 80 µs instant 2: 120 µs instant 3: end of your simulation
• for THOM: instant 1: 88 µs instant 2: 131 µs instant 3: end of your simulation