research project : Increasing the fatigue strength of additive manufactured high-pressure components

Can additive manufactured high-pressure components be designed to ensure sufficient fatigue strength, and what influence does autofrettage have on this?

Project name Increasing the fatigue strength of additive manufactured high-pressure components
Project partner
Grantor DFG
Duration from:1.12.2022 to: 31.05.2026

Research field
 E+E & M+M

(E+E > Energy + Environment
I+I > Information + Intelligence
M+M > Matter + Materials)
Project content
Additive manufacturing (AM) can be used to produce structures and components that cannot be achieved using subtractive manufacturing technologies (turning, milling, etc.) or powder metallurgy, e.g. geometries adapted to the load flow or internal curved channels. Thanks to the increased freedom in manufacturing, AM processes offer opportunities for component optimisation in terms of geometry, weight, stress and flow behaviour of fluids, e.g. for internally cooled tools, pumps, components with cooling or heating channels, coolant distributors, components for hydrogen applications and injection systems. However, questions regarding the cyclic material and component behaviour and thus the fatigue strength of such components remain largely unexplored. In particular, the influence of autofrettage on the operational stability of components subjected to high internal pressure is still unknown. Validated design concepts are not available, and the standard use of cyclic loaded, additively manufactured high-pressure components remains out of the question, especially for SMEs. The aforementioned advantages therefore remain untapped. The results of the research project demonstrate the potential of using additively manufactured components with internal channels and intersections. The technologies and calculation methods investigated in the project are intended to enable accurate simulation of both the autofrettage process and the mechanical behaviour of the components, in particular their fatigue strength. This will allow structurally and fluid-mechanically optimised AM components with internal channels to be designed and manufactured.