Fatigue is still the cause for the majority of mechanical failures in many structural applications, and a typical fatigue failure has at least 3 stages: crack initiation, crack propagation, and final fracture. It is well established that surface defects (e.g. surface roughness), volumetric defects (e.g. pores, lack of fusion), and microstructure are influential factors on fatigue performance of metallic materials. It is also worth noting that cracks often nucleate from/near the surface due to several reasons such as easier inelastic deformation, higher stresses/strains from external loads, and stress concentration effects.
Our Jilin University team is committed to researching and solving fatigue test problems of various materials. The main results include electro-hydraulic servo dynamic and static fatigue testing machine, dynamic and static universal fatigue testing machine, and ultra-high frequency fatigue testing machine. This series of fatigue testing machines has the characteristics of high stability and strong reliability among similar products. Among them, the ultra-high frequency fatigue testing machine can reach a frequency of 450HZ.