Discussion Forum

Hi All,

I have a question using the piezoelectric devices interface and the electrostatics problem. My problem is like this, I bend a thin sheet of material (apply initial displacement at the centre) to form a wrinkle. From this, the material is known to be piezoelectric and anisotropic and in my piezoelectric material I have applied the elasticity stiffness tensor, piezoelectric coupling matrix and relative perimittivity all as anisotropic values. No problems for convergence or solutions, however, I wanted to ask the main differences between the electric displacement field D and the surface charge density rho. According to the users guide the surface charge density is curlD = rho from Maxwells equations. In my simulation, from the wrinkle formation from the initial displacement, I can view the electric potential, electric field, polarisation field and electric displacement field, however, my surface charge density is zero.

I want to calculate the number of charge carriers/cm^2, however, for my situation the curl function of my electric displacmeent field is zero everywhere, in a physical sense does this mean that my electric displacmeent field is the charge carriers/area (C/m^2 to charge carriers/cm^2) but there is no rotation in this field hence why the curlD = rho = 0?

I want to upload an image, however, its a little hard to do on the forum box. Just to summarise why do I have the electric displacement field with say 1e11 charge carriers/cm^2 but the surface charge density is zero?

Does anybody have any suggestions or remarks for this question Your help is most appreciated.

Kind regards, Tanju