Actas de congresos
Application of one-bit time reversal technique to mechanical strain monitoring in plates
Fecha
2014-09-03Registro en:
IEEE International Ultrasonics Symposium, 2014,Chicago, Illinois
Autor
Kubrusly, Alan Conci
Braga, Arthur M B
Von der Weid, Jean Pierre
Perez, Nicolas
Adamowski, Julio Cezar
Oliveira, Timóteo Francisco de
Institución
Resumen
This paper presents the application of the one-bit
time reversal technique to a longitudinal strain sensor. The setup
consists of a pair of piezoelectric transducers bonded in the
extremities of a strip of aluminum plate. When the plate is
subjected to traction, time reversal focalization is performed, the
mismatch between the impulse response at initial and strained
levels causes loss in the focusing quality. The strain can be
evaluated by measuring either the time of flight shift or the
amplitude decrease in the focused signal. One-bit time reversal
can simplify the electronic device to perform the proposed
technique. In this work, the results using one-bit and normal time
reversal implementation were compared. Experiments were
performed using three different 2-2 piezocomposite transducers
pairs at 500, 1000 and 2250 kHz. The longitudinal strain was
applied up to 150 u- strain using a strain gauge as a reference.
The time reversal energy efficiency was used as a spectrum figure
of merit and obeys the sensitivity behavior. The one-bit time
reversal variation provided good focused signal for all
experiments and no significant loss in focus quality. Moreover,
every configuration showed a higher sensitivity than its normal
time reversal version, at least 10% depending on the transducer.
The one-bit technique reveals an important enhancement for the
method; it holds the natural advantage of being simpler and the
benefit of higher sensitivity.