A novel high-frequency fatigue testing methodology for small thin-walled structures in the HCF/VHCF regime

Abstract

A novel high-frequency testing methodology for small thin-walled component-like structures is presented that enables fatigue tests up to 1e9 cycles within 7–8 days. A shaker excites the designed thin-walled (min.0.1 mm) specimen near its resonant frequency and a non-contact relative displacement measurement allows to set a defined notch stress. Calculated and experimentally determined resonant frequencies deviate max.by −1.9%. Furthermore, vibration and temperature measurements prove the stability of the technique, no self heating of the specimen is detected. Validation tests with an X5CrNiCuNb16-4 steel show a typical S-N behaviour for this material, whereby cracks always appear in the intended notch.