Additively manufactured components with functionally graded surface-based meso-structures

• Applicants: Professor Dr.-Ing. Eckhard A. Kirchner; Professor Dr.-Ing. Christian Mittelstedt
• Subject Area: Lightweight Construction, Textile Technology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 572832167

The aim of the project is to develop a method for designing components with lightweight structures based on regular, graded unit cells. This requires models that make the existing shape-property relationships of regular, representative elementary cells in the literature mechanically consistent for analysis and synthesis in product development. Other influencing but uninvestigated characteristics on the load-bearing capacity, such as the choice of metallic material, are considered essential for the method. Furthermore, models are required that make the graded meso-structure based on a given elementary cell accessible for dimensioning by means of elementary internal forces of mechanics and allow an estimation of stiffness and strength. A further model must support the modeling of active surfaces that connect to the graded meso-structure and enable the application of force. Care is taken here to ensure that there is no jump in stiffness that would cause a predetermined breaking point. In addition, the resulting component must be modeled with its functional surfaces and tested for manufacturability with regard to the process-specific manufacturing restrictions of additive manufacturing. The resulting method combines the particle models for analysis and synthesis for quasi one-dimensional structures and offers a higher-level option for the design of surface-based meso-structures that is independent of the shape of the unit cell. The consideration is focused on meso-structures under static loading, which are derived from a unit cell with periodic boundary conditions and constant orientation relative to the component coordinate system. Parallel active surfaces with a constant angle are selected with regard to the force application. The elementary cell geometry is based on the literature. In order to achieve the objectives, four work packages are necessary, each of which is based on an assigned working hypothesis (AH): AH1: For common elementary cells of area-based structures, the stiffness and strength relevant properties can be reduced to single parameters for dimensioning at constant cell size depending on local shape characteristics. AH2: The effect of a stress-appropriate thickness grading of the meso-structures on the stiffness and strength-relevant component properties can be described depending on the characteristics of the grading and can therefore be used for dimensioning. AH3: The connection of active surfaces to the meso-structure can be designed by grading or local feature adjustment without strength-reducing notches. AH4: The resulting analysis and synthesis models can be summarized in a consistent method for the design of and with mesostructures.

• DFG Programme: Research Grants