Experiments on the dynamic Poisson's ratio of PUR foams

Abstract

AbstractPolyurethane (PUR) foams are used in various industrial applications, including vibration damping and noise reduction. Because the effective mechanical properties are needed for the engineering design process, this work presents a method to measure the dynamic Poisson's ratio for the typical range of sound frequencies. A hydraulic pulse testing machine is used to apply the harmonic displacement excitation of the cylindrical specimens for 1 − 100 Hz. The analysis of the time‐dependent deformation data is based on video recordings of a high‐speed camera and a specially derived image processing algorithm.For the Poisson's ratios of the measured foams no significant frequency dependence was found. For PUR foam with an open‐cell or mixed‐cell microstructure the dynamic Poisson's ratio is approximately 0.3. Poisson's ratios of about 0.4 were measured for PUR foams with a high density and a closed‐cell microstructure.