Assessing Acoustic Insulation Measures: A Benchmarking Workshop

Abstract

As part of the Mechathon competition, our objective was to evaluate the effectiveness of soundproofing measures applied to a sound radiating surface. The testing environment comprised a sealed enclosure fitted with soundinsulating materials, housing a loudspeaker for acoustic excitation. The sound-emitting front was designed to be interchangeable, allowing for the testing of various steel plates with and without acoustic measures, including meta-materials, sound insulation mats, and multilayer panels. The goal was to assess simple yet industrially applicable acoustic insulation measures. This investigation, carried out by researchers from German Aeorspace Center (DLR), Fraunhofer Institute for Structural Durability and System Reliability (LBF), Fill GmbH and Linz Center of Mechatronics GmbH (LCM), was approached by teams of two individuals each during the Mechathon event. The teams presented their respective acoustic insulation measures, with a specific emphasis on quantifying the impact of openings in the sound-emitting front – examining how such gaps affect the sound-absorbing properties. To facilitate a comprehensive comparison of each sound-absorbing solution, we utilized a sound intensity probe mounted on a collaborative robot. This probe autonomously conducted sound intensity mapping for each sound-insulating plate, offering a detailed analysis of their performance. The investigation findings indicate that, despite only a minor gap in the sound radiating surface, the efficacy of the soundproofing measures is compromised, if not entirely negated. Additionally, a special focus is on the coupled multi-physics finite element simulation of the mechanical and acoustical domains of the test setup, enabling a deeper understanding of the effects involved. The simulation model is validated through comparison with the experimental results, ensuring its accuracy and reliability.