Discussion Forum

Dear All,

I am interested in the electromechanical problem of voided charged polymers. A conceptual explanation and a 1-D model is depicted in the referenced paper [1]. It is basically a solid polymer material with gas voids which are charged in away to induce surface charges at the void surfaces. I am not interested to model the charging mechanism but the electromechanical response of such a material. I tried building an electromechanics model with time dependent solution. I defined defined voids and surface charges, dielectric properties of polymer solid and gas, mechanical properties of solid and a harmonic applied pressure at the surface of the polymer. The model works and can solve for the electric potential at the outer surface of the polymer but does not show any induced surface charges at such surfaces, which is in contrary to what the model in [1] suggests. The model in [1] is derived from the same equations used in electromechanics model including Gauss's Law and solid mechanics laws. I see a defect in my work in defining surface charge density which should be changing with deformation. I can't find how I could define a constant charge on a surface in this case the charge density will be changing with deformation but the charge will remain the same. Same for the charges induced in the outer surfaces. I wish to know if such a simulation is possible or not.
[1] Hillenbrand, J., and G. M. Sessler. "Piezoelectricity in cellular electret films." Dielectrics and Electrical Insulation, IEEE Transactions on 7.4 (2000): 537-542.
Thanks
Khaled