The first step to construct OPCM elements is to design the piezoelectric phase of the element.
In order to obtain the frequency response of OPCM sensor element and set the range of frequency, the oscilloscope was used to record the waveform from two different directions in the experiment.
The resonance frequency of the OPCM sensor in direction 3 is 173 kHz.
The OPCM elements should be polished first before pasting it to the surfaces of the iron plate and concrete specimen with AB glue.
The dashed lines indicate the test lines of the polarization direction of sensing elements of the OPCM sensor.
In the test, the signals are collected from the iron plate and concrete along the direction of polarization of the OPCM sensing element and at every 15[degrees] along the direction from 0[degrees] to 90[degrees] for different lead lengths.
Three typical waveforms tested by OPCM SAW sensors were selected to analyze.
The OPCM sensor was stuck on the surface of iron plate and concrete specimen.
The developed AE tests are successfully conducted to study the wave propagation phenomena in the iron plate and concrete specimens using the 1-1 OPCM sensor.
Tao, "The OPCM strain gauges for strain and stress measurement of orthotropic material structures," Acta Mechanica Solida Sinica, vol.
Yuan, "Design of an OPCM phased array transducer for damage detection in a concrete structure," Research in Nondestructive Evaluation, vol.