To improve resolution of in-situ measurement crack closure and opening in fatigue, potential drop (PD) technique has been further developed to measure thousands times through each load cycle with high precision. The results are interpreted physical phenomena like strain, Poisson’s effect, piezo-resistivity, plasticity, growth. Application the fatigue growth tests on aluminum 2024-T3 CCT specime...

Exploring crack growth behaviour is needed to establish accurate fatigue life predictions. Cracked specimens were tested under strain-controlled out-of-phase thermomechanical conditions. The tests included dwell times and three different minimum temperatures. Higher temperature gave faster rates while the additions of showed no effects. Crack closure was observed in all where addition change di...

Gas turbine operating cycles at high temperatures often consist of load reversals mixed with hold times; the latter occurring either as cruise for aero engines or at continuous power output for land based turbines, but also at low frequency loading conditions, e.g. slow “ramp up” of engine thrust. The hold time conditions cause the crack to grow by intergranular fracture due to material damage ...