Deformation under electrical field
The deformation caused by the applied electric field can be defined by the simple formula:
Where
● S i =Δx i /x i =ΔL/L and represents the strain (relative deformation) of the sample in the x i direction
● d 31 is the piezoelectric strain constant
Example of an element with the following characteristics:
Length: l=1cm
Width: w=2mm
Thickness: t=9µm
Applied voltage: V=200V -> E (electric field) = V/t
(d 31 , d 32 , d 33 ) = (11, 10, -30) pC/N
The piezo strain constant d is given by:
Sensors: Orders of Magnitude, Voltage generation
The electrical field output (E) caused by an applied force can be defined by:
Where:
● σ i is the applied mechanical stress (N/m²)
● g ij is the piezoelectric voltage constant (Vm/N)
Example of an element with the following characteristics:
Length: l=2cm
Width: w=2cm
Thickness: t=100µm
Compression 0.1 Bar (104 Pa) 4N -> σ=10000N/m²
