The capabilities of detection and localization of damage in a structure, using a guided wave-based structural health monitoring (GWSHM) system, depend on the damage location and the chosen sensor array setup. This paper presents a novel approach to assess the reliability of an SHM system enabling to quantify localization accuracy. A two-step technique is developed to combine multiple paths to generate one probability of detection (POD) curve that provides information regarding the detection capability of an SHM system at a defined damage position. Moreover, a new method is presented to analyze localization accuracy. Established probability-based diagnostic imaging using a signal correlation algorithm is used to determine the damage location. The resultant output of the localization accuracy analysis is the smallest damage size at which a defined accuracy level can be reached at a determined location. The proposed methods for determination of detection probability and localization accuracy are applied to a plate-like CFRP structure with an omega stringer with artificial damage of different sizes at different locations. The results show that the location of the damage influences the sensitivity of detection and localization accuracy for the used detection and localization methods. Localization accuracy is enhanced as it becomes closer to the array’s center, but its detection sensitivity deteriorates.

The Model-Assisted Probability of Detection (MAPOD) approach is a promising technique for cost-effective and time-efficient assessment of the reliability of Guided Wave Structural Health Monitoring (GWSHM) systems. While it has the capability to generate statistically independent datasets, it has a weakness in taking into account the influence of structural, environmental and operational parameters. This paper presents one possible solution to addresss this weakness. The approach is based on combining simulated damage scenarios with data taken from a real GWSHM system at the undamaged stage and under the influence of these parameters. The resulting dataset is then processed using the conventional POD analysis. The approach is demonstrated on a steel pipe with a GWSHM system employing an array of PZT shear elements bonded around the circumference of the pipe to excite a fundamental torsional mode, T(0,1). Different damage sizes are simulated, taking into account small pipe thickness variations. Finally, the simulation dataset is combined with the experimental one to generate a realistic, specific POD curve for that system.