Fatigue life of notches: an effect of manufacturing

Abstract

In this study, the influence of notches in the area of gigacycle fatigue is investigated. The presented study offers experimental fatigue results of smooth and notched specimens. Specimens were made of AW 7075 - T6511 aluminum alloy and have “v” shape notch with radii of 0.1, 0.2, 0.4, 0.8, 1.5, and 3 mm. The fatigue experiments were performed using an ultrasonic fatigue testing machine at 20 kHz test frequency. Fatigue properties of the material were studied and evaluated up to 10 billion cycles in the area of very high cycle fatigue. All fatigue tests were carried out under uniaxial symmetric tension/compression loading (R=-1) at room temperature. As-machined surface and fracture surface of smooth specimens and specimens with 6 different notch radii were observed under an SEM microscope. Results show that there is a strong influence of the manufacturing process on fatigue lifetime.In this study, the influence of notches in the area of gigacycle fatigue is investigated. The presented study offers experimental fatigue results of smooth and notched specimens. Specimens were made of AW 7075 - T6511 aluminum alloy and have “v” shape notch with radii of 0.1, 0.2, 0.4, 0.8, 1.5, and 3 mm. The fatigue experiments were performed using an ultrasonic fatigue testing machine at 20 kHz test frequency. Fatigue properties of the material were studied and evaluated up to 10 billion cycles in the area of very high cycle fatigue. All fatigue tests were carried out under uniaxial symmetric tension/compression loading (R=-1) at room temperature. As-machined surface and fracture surface of smooth specimens and specimens with 6 different notch radii were observed under an SEM microscope. Results show that there is a strong influence of the manufacturing process on fatigue lifetime.