Fundamentals of consistent characterization and design of WAAMmanufactured steel components at high deposition rates

• Applicants: Professor Dr.-Ing. Markus Feldmann; Professor Dr.-Ing. Uwe Reisgen
• Subject Area: Structural Engineering, Building Informatics and Construction Operation ; Joining and Separation Technology ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 539093885

Wire-Arc-Additive-Manufacturing (WAAM) opens up extraordinary perspectives for new design and application possibilities in steel construction. However, both the technology with regard to the production speed required in steel construction and the steel construction design, taking into account the process- and componentrelated irregularities of geometry and structure, are still unexplored in many areas. The manufacturing technology and the design characteristics of components manufactured with WAAM are closely related. The subject of this project therefore is the research of the fundamentals necessary for steel construction to create increased deposition rates and manufacturing safety in the field of WAAM, the geometrical and structural property characterization, as well as the fundamentals of a design of WAAM-manufactured steel components with "free form" consistent with manufacturing and characterization. On the manufacturing side, this concerns the increase of the deposition rate with reliable estimation of distortion and residual stresses, the optimization of the production result in mechanicaltechnological terms, taking into account the wire materials that can be used, and the further development and integration of the automation processes. This also applies to parameterization, control and path curve programming. After the clarification of topologies that are principally practicable, the questions are further related to finding suitable parameter constellations of the manufacturing process in order to reliably achieve the desired material and geometric properties, as well as to the characterization of the manufactured component in terms of material and geometry. In addition to strength distributions and the influence of internal stresses, surface roughness, resulting thickness deviations and waviness of the component wall influence the characteristic values for geometry and material to be used for the design. Statistical characteristics are derived for this purpose. Then a concept of manufacturing classes is aimed at, whose characteristic features are taken up again by the design. For this purpose, the expected component shapes and design cases as well as the production including automation have to be considered. Manufacturing and dimensioning must be coordinated with each other, since the structural-mechanical properties of the component depend on the production-related characteristics. Based on this, the questions of design refer to a verification concept that is as practical as possible and in which the various design cases can be embedded. Taking into account the material and geometry deviations resulting from the WAAM process, the component resistance under tensile stress, the stability behaviour as well as the fatigue strength are to be investigated with special consideration of the scattering character of the characteristics of the additively manufactured component.

• DFG Programme: Research Grants