Analyzing free and forced vibration of flexible polyurethane foam using multiple time scales method

Abstract

List of symbols k 1 Coefficient of linear stiffness [N/m] k 3 Coefficient of cubic stiffness [N/m 3 ] k 5 Coefficient of fifth power stiffness [N/m 5 ] c Coefficient of linear velocity damping [Ns/m] α i Kernel coefficient of viscoelastic relaxation [1/s] a i Kernel coefficient of viscoelastic relaxation [1/s] z Foam compression [m] Γ Kernel of viscoelastic relaxation x Relative displacement of the mass [m] σ Detuning parameter

Investigation on Compression Mechanical Properties of Rigid Polyurethane Foam Treated under Random Vibration Condition: An Experimental and Numerical Simulation Study

“…However, beyond that, polyurethane foam also was often used as core material to make sandwich board [22,23] and honeycomb board structures [24], because of its good vibration absorption and isolation performance. To understand the vibration characteristics of foam materials, the researchers studied the density, strength, and viscoelasticity of foam materials [25,26]. Lyes Dib et al found through the 3D COMSOL Multiphysics that Young’s modulus, Poisson’s ratio, damping factor, and density of polyurethane foam would change the absorption coefficient, thereby affecting the sound absorption performance [25].…”