FE analysis for microstructure which imitated polyurethane foam

Abstract

Polyurethane foam for sound absorption is used to reduce noise in automobiles, houses, home appliances, etc. Using a 3D printer, we created a model with a simple structure of urethane foam. We created multiple types of shaped objects with spherical cavities with a diameter of several millimeters connected by small cylindrical holes with different diameters of spheres and cylinders, and measured the vertical incident sound absorption coefficient using an acoustic tube. We also created an FE model with the same shape and calculated the sound absorption coefficient. It was confirmed that the peak frequency of the sound absorption coefficient approximately coincided with the Helmholtz resonance frequency. In addition, the above test piece model was created with a finite element model, which was in good agreement with the experimental results. A skeletal parameter study was conducted to investigate the effect on sound absorption.