Probabilistic Diagnostic Algorithm for Identification of Multiple Notches Using Digital Damage Fingerprints (DDFs)

A probabilistic damage diagnostic algorithm based on correlation analysis was investigated to locate single or multiple damage. To highlight the changes in signals corresponding to the presence of damage, digital damage fingerprints (DDFs) were extracted from the captured Lamb wave signals. The algorithm was validated through experimental studies where dual artificially introduced notches in an aluminum plate were successfully located using the constructed images of the probability of the presence of damage. Damage identification using either the captured wave signals or their DDFs agreed well with the actual situations. The concept of virtual sensing paths (VSPs) was proposed to enhance the performance of the algorithm. The results demonstrated that the correlation-based algorithm with the applications of DDFs and VSPs was capable of identifying multiple damage in plate-like structures.