Numerical methods for stress intensity factor ΔK calculations of fretting cracked interface

Plain fretting experiments generate cracks under partial slip conditions. The maximum projected crack length (bp) related to the fretting crack achieved after a certain number of cycles is measured and the corresponding stress intensity factor range ΔK is computed. This work compares several methods for computing ΔK: a classic approach using McEwen's distribution, an indirect method using FE simulation and weight functions (decoupled approach), and complete FE simulations using Rice's integrals (coupled approach). The decoupled approach is faster than the coupled one and gives conservative results for long cracks whereas for shorter cracks and for a better approximation, the coupled approach is more relevant. The present study is limited to plain fretting cylinder (Ti-6Al-4V)/flat (Al-7050-T7451) configuration in partial slip. •A reverse analysis is used to extract fatigue ΔK0 from fretting experiments.•Several methods to compute ΔK at a fretting crack arrest condition are compared.•Two numerical models, “coupled” and “decoupled” were specially developed.•The balance between time and error's prediction is determined.•The use of quadratic or linear elements for the FEM computation is discussed.