Digital Wideband Excitation Technique for Impedance-Based Structural Health Monitoring Systems

With ever increasing complexity in new mechanical structures, as well as aging structures in operation, locating damage with structural health monitoring techniques is becoming increasingly important. Permanent deployment of structural health monitoring systems is limited by the availability of sensor technology. Previous efforts to miniaturize the hardware required for the impedance method of structural health monitoring resulted in prototypes reliant on a DAC for providing excitation to the structure of interest. In this paper, a new excitation technique using wideband digital signals is proposed to eliminate the power dissipated by a DAC in the system. An experiment is performed to compare performance of the proposed technique and previous excitation techniques. Results are presented and reveal no loss in damage detection performance while reducing the power dissipation.