Numerical modeling of crack propagation and shielding effects in a striping network

Thermal fatigue cracking is observed in some components of nuclear power plants. The residual lifetime prediction of cracked components is necessary to determine maintenance programs. An automatic procedure is developed for 2D modeling of multiple crack propagation within the finite element software Code_Aster® to evaluate the crack growth rate and shielding effects in a multicracked structure in thermomechanical fatigue. It consists in a global remeshing method to model crack growth and includes a propagation strategy based on the crack length increment. A set of parametric studies is analyzed for a cracked pipe to evaluate the influence of geometrical and loading parameters on the residual lifetime of the crack network.