Adaptive multiscale anisothermal fatigue crack propagation in a combustion chamber

This video presents a numerical simulation of crack propagation under thermo-mechanical fatigue loading in an aircraft engine combustion chamber. It uses adaptive multiscale modeling, to represent on-the-fly a realistic microstructure (grain size around 60-80 microns) in the initiation zones in the "short crack" regime, which transforms into a homogeneous medium when the Paris regime is reached.

In order to highlight the flexibility of numerical approaches, the physical model has been simplified: the loading cycle is defined between a quiescent state and a state of maximum thermal stress, the material behavior is linear elastic (but anisotropic in microstructures), propagation laws are based on Paris-type models with crack orientation according to the MTS criterion.

Such a simulation, carried out with the Z-set/Z-cracks code, on 382 propagation steps, requires less than 11h of computing time on a laptop: from 1min20 per calculation step (FE computation, SIF post-processing, propagation law and remeshing) with a homogeneous model of around 400kdofs, to 3min in multiscale for 650kdofs.

This work was supported by ANR SEMAFOR 14-CE07-0037.

• #science_technology
• #fatigue
• #crack_propagation
• #finite_elements
• #adaptive_remeshing
• #multiscale