On the use of piezoelectric sensors for experimental modal analysis

Piezoelectric disk buzzers are commonly used on stringed musical instruments to acquire the sound in the form of a voltage signal. Aim of the present investigation is to assess the possibility of using these transducers for experimental modal analysis. Piezoelectric disks were therefore used in the laboratory to extract the natural vibration frequencies and mode shapes of an aluminum cantilever beam and of a steel arch. The results are compared with theoretical predictions and with other experimental values obtained using a laser displacement transducer and accelerometers. Due to their high accuracy, small dimensions, low weight, easy usage, and low cost, piezoelectric disks seem to be an attractive tool for experimental modal analysis of engineering structures.