• Misol, Malte
• Di̇nçer, Uğur
• Monner, Hans Peter

Abstract

Membrane-type acoustic metamaterials fall into the categoryof metamaterials with locally resonant behavior. Adjustingthe unit cell properties brings the opportunity to tuneresonance/anti-resonance frequencies. Moreover, noiseattenuation might be achieved in the desired frequency rangeusing artificially engineered lightweight structures.Conventional methods for the realization of membrane-typeacoustic metamaterials cause such uncertainties on thefundamental parameters: positioning and shape limitation ofthe masses and adjustment of membrane pre-stress.Subsequently, those methods are time-consumingconsidering large-scale structure fabrication. Additivemanufacturing approaches minimize the side effects causedby conventional methods with a repeatable and robustprocess. In this research, various membrane-type acousticmetamaterial unit cells are manufactured using multimaterial printing via the fused deposition modeling (FDM)method. Flexible (TPU) filament is used for the membrane,while relatively rigid filament (PETG) is chosen for theframe and the masses. Initially, the unloaded unit cells areexamined in order to evaluate 3-D printed membrane prestress and repeatability of the fabrication approach.Afterwards, the effects of membrane and mass properties onthe sound transmission loss (STL) behaviors of the unit cellsare investigated using an impedance tube in order toimplement in multi-celled membrane-type acousticmetamaterials.

Topics

• Deposition
• impedance spectroscopy
• metamaterial
• additive manufacturing