Figure 4

(a) Schematic illustration of the experimental setup for GLWs propagation on an aluminium plate-like sample. The PC waveguide and a surface bonded piezoelectric transducer are used as ultrasonic wave transmitters, whilst a second piezoelectric sensor is employed to acquire the material nonlinear elastic response. Whilst the transmitter transducers are connected to a signal generator and an amplifier, the receiver sensors are linked to an oscilloscope and a computer to process the measured waveforms. (b,c) Experimental material response measured by the receiver sensor using an amplified input voltage of 125 V and a driving frequency (b) \({f}_{0}\) = 100 kHz and (c) \({f}_{0}\) = 150 kHz. In both figures, the blue dashed line is the waveform acquired with no transmitter PC waveguides, whereas the dashed red and continuous black lines are the signals recorded using the aluminium and ABS PC sensing devices, respectively.