Taking residual stresses into account in low-cycle fatigue design using the adjustable localisation operator method

Bruno Levieil (1, 2) , Cédric Doudard (1, 2) , David Thevenet (1, 2) , Florent Bridier (3) , Anthony Ezanno (4) , Sylvain Calloch (1, 2)

1 ENSTA Bretagne - École Nationale Supérieure de Techniques Avancées Bretagne
2 IRDL - Institut de Recherche Dupuy de Lôme
3 Naval Group
4 DGA - Délégation générale de l'armement

This paper assesses the ability of the Adjustable Localisation Operator (ALO) method to predict the influence of residual stresses on the fatigue behaviour of notched components. Different initial residual stress states are introduced into notched specimens, which are then tested under cyclic loadings in a fatigue range of 103 to 105 cycles. Experimental comparisons with initially stress-free specimens have shown how tensile residual stresses reduce fatigue life under repeated compressive loading while compressive residual stresses increase fatigue life under repeated tensile loading. Finite Element Analysis (FEA) and ALO method predictions of changes in residual stress are compared to experimental measurements beforehand to assess fatigue life predictions. A modified version of Morrow’s criterion is used to account for the mean stress effect. Results have shown that the ALO method can predict the influence of residual stresses on low-cycle fatigue with the same accuracy as finite element analysis and with a significant reduction in computation time.

Keywords: Plastic zone; Simplified method; Notches; Load ratio; Residual stresses

Domains: Materials and structures in mechanics [physics.class-ph]

Bruno Levieil, Cédric Doudard, David Thevenet, Florent Bridier, Anthony Ezanno, et al.. Taking residual stresses into account in low-cycle fatigue design using the adjustable localisation operator method. International Journal of Fatigue, 2021, 150, pp.106322. ⟨10.1016/j.ijfatigue.2021.106322⟩. ⟨hal-03293680⟩