Symbols and Units

A Surface area [m²] (meter²)
α Coefficient of Thermal Expansion (CTE) [K-¹] (1/kelvin)
C Capacitance (F) [A s / V]
dij Piezo modulus (tensor components) [m/V] (meter/volt)
ds Distance, thickness [m] (meter)
Є Dielectric constant [A s/V m] (ampere second volt meter)
E Electric field strength [V/m] (volt/meter)
f Operating frequency [Hz] (hertz = 1/second)
F Force [N] (newton)
f0 Unloaded resonant frequency [Hz] (hertz = 1/second)
g Acceleration due to gravity: 9.81 m/s² (meter/second²)
i Current [A] (ampere)
kS Stiffness of restraint (load) [N/m] (newton/meter)
kT Stiffness of piezo actuator [N/m] (newton/meter)
L0 Length of non-energized actuator [m] (meter)
∆L Change in length (displacement) [m] (meter)
∆L0 Nominal displacement with zero applied force, [m] (meter)
∆Lt=0.1 Displacement at time t = 0.1 sec after voltage change, [m] (meter)
m Mass [kg] (kilogram)
P Power [W] (watt)
Q Charge [C] (coulomb = ampere x second)
S Strain [L/L] (dimensionless)
t Time [s] (second)
U voltage [V] (volt)
Up-p Peak-to-peak voltage [V] (volt)