Define Material Properties
Define material properties for the piezoelectric materials. The material library contains several common piezoelectric materials under the piezoelectric section. If you want to define your own piezoelectric material, you need to specify its properties by hand. The required properties depend on whether the constitutive relations are in stress-charge or strain-charge form, and which damping and loss attributes are created. Defining all piezoelectric settings before materials preselects the required properties and makes the completion easier:
Mechanical Properties
•
Density rho (SI unit: kg/m3)
•
Elasticity matrix cE (SI unit: Pa) when Stress-charge form is selected.
•
Compliance Matrix sE (SI unit: 1/Pa) when Strain-charge form is selected.
Electrostatic Properties
•
Relative Permittivity εrS (dimensionless) when Stress-charge form is selected.
•
Relative Permittivity εrT (dimensionless) when Strain-charge form is selected.
Coupling Properties
•
Coupling matrix eES (SI unit: C/m2) when Stress-charge form is selected.
•
Coupling matrix dET (SI unit: C/N) when Strain-charge form is selected.
Damping and Loss Properties
•
Either loss factor ηcE for elasticity matrix cE, or the loss factor ηsE for compliance matrix sE: required when Mechanical Damping is present. Both are dimensionless, the latter is valid only when Strain-charge form is selected.
•
Either loss factor ηεS for electric permittivity matrix εrS, or loss factor ηεT for electric permittivity matrix εrT: required when Dielectric Loss is present. Both are dimensionless, the latter is valid only when Strain-charge form is selected.
•
Either loss factor ηe for coupling matrix e, or loss factor ηd for coupling matrix d: required when Coupling Loss is present. Both are dimensionless, the latter is valid only when Strain-charge form is selected.
•
Electric conductivity σe (SI unit: S/m): required when Conduction Loss is present.
Working with Materials and Piezoelectric Materials Library in the COMSOL Multiphysics Reference Manual.