DEDICATED SOLVER : crack propagation

Since 2015, LEMMA has developed a new state of the art XFEM (eXtended Finite Element Method) solver dedicated to crack propagation in 3D. This structural solver allows you to get results :

  • on 3D massive structural parts to handle anisotropic geometries that can be found in aerospace (aircraft) and naval industries (foils, sails),
  • on 3D massive structural parts with possible crack bifurcation,
  • on crack propagation with contacts between the different parts,
  • on very highly complex geometries by the introduction of the intelligent mesh technology that is now coupled with the crack propagation solver.

From a physical point of view, several fatigue laws have been implemented as well and the Ki’s are easily post-processed by the code together with the number of cycles during fatigue crack propagation.

All the crack propagation is handled by the software without any manual inputs from the user.

The software has been parallelized to save time on those applications.

Test case on academic benchmark

The test consists in crack calculation on a simple flat plate. The crack propagation can now be coupled to our intelligent mesh technology to save a factor 10 in CPU time vs more classical fixed mesh approaches. Moreover, it allows us to handle complex and high aspect ratio geometries efficiently within an acceptable time frame for engineering applications.

Flat plate crack propagation case.

Case with intelligent mesh.

Closer view.

Industrial study (courtesy of STELIA)

This case presents a more complex situation where a crack propagates in a volumetric part of the structure around a hole at the very beginning of the simulation. Only a small part of this structure is shown for confidentiality reasons. As it can be seen on the video, two cracks are propagating simultaneously at different speeds. The calculation is done without any manual restart or inputs from the user.

Volumetric hole crack propagation.

Sliced hole crack propagation.