Robust design of additively manufactured acoustic structures

• Applicants: Professorin Dr.-Ing. Sabine C. Langer; Professor Dr.-Ing. Thomas Vietor
• Subject Area: Acoustics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 508318707

Additive Manufacturing like Material Extrusion, offers new freedom in design, due to its principle of layer-by-layer material deposition. Among other benefits, this allows a combination of multiple materials within one part and the realization of undercuts like lattice structures, without additional assembly and joining processes or post-processing. Thus, new possibilities arise for manufacturing and integrating acoustically effective structures with tailored properties to reduce structure-borne and airborne sound.This research project aims to develop a methodology for the robust design of additively manufactured acoustic black holes and porous absorbers. The closely linked cooperation between the fields of acoustics, engineering design and additive manufacturing is the prerequisite for elucidating the event chains – also process-structure-property relations – of acoustic parameters, part properties, process parameters and the design of geometry. A systematic and robust design of acoustic structures with defined parameters is currently still limited by a lack of detailed knowledge regarding the inherent sensitivities between process parameter selection as well as geometry definition and the resulting acoustics-relevant properties.In order to achieve this goal, the dependencies between part properties and acoustic parameters for the specific adjustment of the acoustic function are investigated in this research project for the two use cases of acoustic black holes and porous absorbers, on the one hand. On the other hand, the process-specific influencing factors on the resulting part properties and the geometric features are systematically analyzed. The event chain relationships are systematically determined by means of numerical and experimental investigations and are the basis for a robust design of acoustic structures manufactured by material extrusion. The aim is to identify sensitive and robust event chains in order to achieve a goal-oriented adjustment of the resulting part properties and, thus, of the function with a low uncertainty. To utilize this potential, the knowledge gained will be transferred into a methodology and design rules. The validation of the methodology and the evaluation of the potential of additive manufacturing processes for a robust production of acoustic black holes and porous absorbers with specific properties will finally be achieved by the manufacturing of demonstrators for the two defined use cases.

• DFG Programme: Research Grants