A joined finite element based method to simulate 3D crack network initiation and propagation in mechanical and thermal fatigue

A new finite element method is proposed to model the evolution of cracks in a 3D lattice under mechanical and thermal fatigue loading. This step-by-step method, based on the separation of initiation and propagation phenomenon, is tuned by fitted entrance parameters which command fatigue laws. It is founded on linear elasticity assumptions, and the crack’s evolution is taken into account by a so-called element deletion method. After the algorithm of the model is presented, two examples of mechanical and thermal fatigue are considered. The evolutions of different crack network characteristic parameters as a function of the number of cycles is proposed and match, at least qualitatively, the general trends observed experimentally.

► A FE based method is proposed to simulate the development of fatigue crack networks.
► It allows for 3D simulations and stress redistributions.
► It combines random crack initiation and deterministic crack propagation behaviors.
► It is applied and compared successfully to uniaxial fatigue experimental results.
► It is applied to thermal fatigue and provides encouraging qualitative results.