Dynamic Modulus of Poroelastic Materials

Abstract

A simple mathematical formula is proposed to predict the fluid damping effects in poroelastic materials. Biot’s poroelasticity equations are solved to obtain the response of poroelastic materials undergoing harmonic tension-compression and bending deformation. Complex moduli of poroelastic material are explored from the response functions on basis of mathematical models. It is shown that the effects of material parameters, geometrical parameters, and flow boundary conditions on the fluid damping are predicted by simple mathematical formulas. Numerical results are presented and compared with those of other researchers.

Investigation and modelling of damping in a plate with a bonded porous layer

“…Its location tends to smaller flow resistivity when thickness increases. This is consistent with the calculation of Okuno [8], given for a sealed poroelastic beam undergoing bending deformation…”

“…It shows that viscous and viscoelastic dissipation dominate. According to Okuno [8], viscous dissipation can be optimized by choosing a proper flow resistivity : it becomes the major dissipation mechanism within soft materials. However for stiff polymer foams, viscoelastic dissipation in the skeleton is widely dominating.…”

“…For soft material, damping becomes significant for a thicker layer and only where the viscous dissipation is important : a maximum loss factor of 6% is then reached with 5 cm. However, according to Okuno [8], the optimized value of air flow resistivity depends on the frequency : it is not suitable for a large frequency range.…”

“…In these studies damping effect is shown for various boundary conditions and materials, but no general tendencies is drawn about the nature of dissipation. Other reports give analytical predictions [7,8] of the importance of viscous dissipation induced by the vibration of the skeleton, but they are approximative and limited to 1-D or 2-D applications.…”

Strain-rate effects on elastic and early cell-collapse responses of a polystyrene foam

“…Polymeric foams are strain rate sensitive [15][16][17], but the published results are limited to strains well beyond the initiation of cell collapse. Studies of the elastic behavior of polymeric foams under dynamic conditions have so far been limited to viscoelastic measurements [30,31]. Therefore, we set out to investigate the quasi-static and dynamic behavior of this material in compression at small strains.…”