The primary applications of Structural Health Monitoring are detection and localization of defects in the investigated component. The measurement data collected by the SHM network are initially available as pure A-scans. Considering the associated actuator and sensor positions, imaging results can be calculated from the measurement data, which are comparable to C-scans of conventional ultrasonic inspections.

Figure 1 shows a sensor network with sensors S01 to S15 applied to a plate (gray area). Between the sensors S04 and S09 a defect is inserted as a white recess. Due to the defect, the wave propagation in the signal paths S04 → S09, S03 → S10 and S05 → S08 is most strongly influenced. If the A-scans of all measurement paths are compared with each other before and after the damage occurs, for example via a correlation function, a probability distribution of an existing damage can be calculated for the area of the sensor network (see Figure 2).

Fig. 1: Sketch of a component with a SHM sensor network and a damage between S04 and S09.

Fig. 2: Sketch of the component results generated from the sensor data according to Fig. 1 with color scale for defect probability distribution.