Piezo Ceramics Tutorial 13 of 15

Units & Symbols

Values are SI metric.

	=	Permittivity
₀	=	Permittivity of free space (8.85x10^-12 Fm^-1)
K^T₃₃	=	relative dielectric constant, free
K^S₃₃	=	relative dielectric constant, clamped
tan =1/Q_E	=	dissipation factor at 1kHz, low electric field
k_p	=	planar coupling factor
k₃₁	=	transverse or lateral coupling factor
k₃₃	=	longitudinal coupling factor
k₁₅	=	shear coupling factor
k_t	=	thickness coupling factor (laterally clamped)
d	=	piezoelectric constant, strain/field at constant stress or charge density/stress at constant electric field, 10^-12m/V
g	=	piezoelectric constant, electric/field at constant charge or strain/charge density at constant stress, 10^-3 Volt metres/Newton
S^E	=	elastic compliance at constant electric field, 10^-12 m²/N
S^D	=	elastic compliance at constant charge density, 10^-12 m²/N
Q_M	=	mechanical Q. This is dependent upon configuration, and is given here for a thin disc.
N₁	=	frequency constant of a thin bar, Hz m.
N₃₃	=	frequency constant of a disc or plate poled through thickness resonating in thickness mode
	=	density, 10³kg/m³
T	=	temperature, °C
	=	thermal expansion

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