PUB - Autofrettage and its impact on high-cycle fatigue of hydraulic components


Regulating bodies and aircraft operators place stringent requirements on hydraulic systems for aerospace applications. Systems designed for such applications have to adhere to the highest safety standards, which implies a high degree of redundancy. Consequently, modern-day aircraft have at least two completely independent hydraulic circuits.



Authors: Rambaks, Andris; Bauer, Niklas: Knipper, Paul; Schmitz, Katharina

Aluminium alloys represent a cost-effective alternative to titanium alloys for hydraulic components in the aerospace industry. However, the inferior mechanical properties of these materials have limited their use at high pressures and hence prevented their wider adoption. Application of the autofrettage process overcomes these deficiencies and enables the use of aluminium alloys at high-pressures. In this paper, the impact of autofrettage on fatigue life is investigated by means of FEM simulations and application of the stress-life concept. Numerical calculations demonstrate that by subjecting hydraulic components to the autofrettage process significant increases in the number of cycles until failure are achievable.