Comparison of guided wave sensors for SHM sensor networks

The need for custom-designed sensor networks, tailored to the specific SHM task for practical application of guided waves, is constantly growing. As a prerequisite for a successful development of different monitoring concepts the transducers wave excitation and receiving properties have to be known. The more exactly they are understood the more reliable monitoring concepts are possible. Nowadays different piezoelectric transducer concepts, with varying acting principles having their specific advantages, are used in SHM applications. Strongly unequal properties concerning source density and directivity patterns are revealed. Hence, a method is introduced by which different transducer types can be compared in respect to their efficiency in exciting and receiving guided waves. Furthermore a reciprocity-based model for the estimation of the maximum transducer to transducer distance is applied and discussed.