Abstract
In general, the electromechanical impedance-based SHM method uses a
piezoelectric transducer as a sensor/actuator to excite/measure the
dynamic response of a mechanical structure under investigation in order
to find incipient damage. The SHM method requires many samples of
impedance signatures to analyze the behavior of the system and draw a
diagnostic. This contribution proposes a method to generate new
impedance signatures as based on a number of measured signatures. The
signature generator operates through the Monte Carlo method. Thus, this
approach proposes to drastically reduce the number of measured/recorded
samples that are normally used in the impedance-based SHM. This
reduction can be as large as 93\%. For this aim, a case
study is proposed, namely, an “I” profile structure with four levels
of damage (mass addition). Moreover, 33 impedance signatures for each
level of damage were measured. Then, the Monte Carlo method was used to
generate 400 virtual signatures. Finally, the generated signatures were
compared with the experimentally acquired ones in order to measure the
error associated with the generated signatures. In conclusion, this
contribution presents a method that uses the properties of the impedance
signatures to store them and, if necessary, to use these signatures to
generate numerical ones, thus reducing the need for storing a large
amount of data and lessen the number of experimental impedance
signatures acquired over time.