Probabilistic relationships between strain range, stress range and loading cycles. Application on ASTM A969 steel

Abstract

Fatigue life estimations can be made by considering the Δσ-N or Δ∊-N curves. Reliable estimations allow engineers designing save stress levels in structures or machines. In this paper, the Weibull distribution is combined with the Stüssi function to model the quantiles of the Δσ-N and Δ∊-N curves and the Ramberg-Osgood relationship. The nonlinear Stüssi function offers a good geometric approach to model the relationship Δσ-N or Δ∊-N and the Weibull distribution is the most adequate to handle lifetime magnitudes as load cycles N. To show the application of the proposed model, simulated and experimental data of ASTM A969 steel are evaluated.