Unraveling the myth of closure corrections: Sharpening the definition of opening and closure stresses with an energy approach

The substantiation of fatigue crack closure corrections is disputed, based on the closure stress definition. The ΔK_eff equation lacks a physical explanation. An inconsistency is observed between the opening stress S_{op_phen} as used by this equation and the physical opening stress S_{op_phys}....

Measuring crack growth and related opening and closing stresses using continuous potential drop recording

To improve resolution of in-situ measurement of crack closure and opening in fatigue, potential drop (PD) measurement technique has been further developed to measure thousands of times through each load cycle with high precision. The results are interpreted with physical phenomena like strain, Poisson's effect, piezo-resistivity, plasticity,...