Harmonic vibration test for the analysis of the dynamic behaviour of polyurethane foams

Olivier Duboeuf (1, 2) , Raphaël Dupuis (1) , Evelyne Aubry (1) , Marc Lauth (2)

1 MIPS - Modélisation, Intelligence, Processus et Système
2 Laboratoire R&D Foam Chemistry

The main goal of this paper is to describe experimental techniques and identification of dynamic properties of flexible polyurethane foam. Indeed, automotive seat comfort level is established with considering quasi-static—density core, hysteresis loss and compression stress— and dynamic— transmissibility and damping— properties of flexible polyurethane foams. Our dynamic system, modeled as a single degree-of-freedom system, is composed of an experimental device with a free mass on the top and a shaker on the basement. The first one, a rigid block, is mounted on a 100 × 100 × 50 mm cube sample of foam material and the second one excites the device with harmonic vibration. The steady-state response of a polyurethane foam sample—after the same number of cycles—to harmonic vibration is analyzed for different excitation amplitude level and for different initial compression level, corresponding respectively to various road surface conditions and to various apparent-mass. The transmitted vibration between the shaker and the free mass is measured to determine the damping effect and the filter band of polyurethane foam, and enables to trace the Bode magnitude and phase plots of the dynamic stiffness function of the system. The results presented here compare three types of foams.

Mots clés: polyurethane foams; dynamic behavior; dynamic stiffness function; harmonic vibration; Bode plots

Domaines: Mécanique des matériaux [physics.class-ph]; Vibrations [physics.class-ph]

Olivier Duboeuf, Raphaël Dupuis, Evelyne Aubry, Marc Lauth. Harmonic vibration test for the analysis of the dynamic behaviour of polyurethane foams. Journal of Dynamic Behavior of Materials, 2016, 1, pp.61-67. ⟨10.1007/978-3-319-22452-7_10⟩. ⟨hal-01510117⟩