A piezoelectric transducer is an electromechanical sensor which converts
electrical energy (voltage signal) to mechanical energy (displacement
signal) and vice versa by taking advantage of the piezoelectric crystal.
Depending on the physical combination of transducer parts, sensors may have
a linear or non-linear response to the input signal. In seismic tests such
as ultrasonic non-destructive testing (NDT) methods, analyzing stress wave
propagation through the specimen gives an assessment of its condition. The
signal attenuation is an important parameter to assess the condition of
specimen which can be done by having the displacement signal as an output.
However, instead of the displacement signal, the piezoelectric transducer
provides the voltage signal as an output. Therefore, to get reliable and
accurate results, it is essential to calibrate the transducers. An
appropriate calibration results in a suitable Transfer Function (TF) which
can be used to properly calculate the displacement signal. In this study,
the output displacement of a 1 MHz piezoelectric transducer is measured
using a laser vibrometer with a nanometer resolution. Measurements and
calculated TF showed at frequencies of 0.1, 1, and 1.5 MHz, TF values are
0.8, 0.08, and 0.2 respectively which is a non-linear relation between
displacement (absolute signal) and voltage (relative signal) as it was
expected. Then, numerical simulation is implemented as part of this study to
simulate all electrical and mechanical components of the piezoelectric
transducer. The simulation was verified with the absolute displacement
measurements result from the laser vibrometer.
Energy Evolution Law of Marble Failure Process Under Different Confining Pressures Based on Particle Discrete Element Method
