A weighted correction of RAPID for precise damage localization in composites using guided waves and principal component analysis

Abstract

Composite materials are widely used in various engineering applications such as aerospace, automotive, construction, and sports equipment due to their superior mechanical properties, including a high strength-to-weight ratio, design flexibility, and resistance to fatigue and corrosion. However, the complex nature of composite materials and their damage mechanisms poses a challenge to effective Structural Health Monitoring (SHM). Guided waves have been shown to be an effective non-destructive testing technique for localizing damage in Carbon Fiber Reinforced Polymer (CFRP) materials when used with the RAPID (Reconstruction Algorithm for Probabilistic Inspection of Damage) algorithm, which has high robustness and efficiency. However, in some cases, the RAPID algorithm may suffer from inaccuracies in predicting damage positions due to the intersection points among transducer paths. To address this issue, this paper proposes a correction to the original RAPID algorithm. The correction introduces weights to the probability of damage position, computed from the number of intersections that cross that position, to mitigate the impact of the intersection problem. Additionally, the Q-statistic, which is calculated through principal components analysis (PCA), is employed as a damage position indicator. To evaluate the effectiveness of the proposed correction, the measurement data from 12 transducers mounted on a 500 × 500 mm CFRP plate with a reversible damage model placed in different positions are used. The results of the proposed method are compared to the results of RAPID, a suggested geometrical correction of the RAPID algorithm. The findings demonstrate that the proposed correction provides an effective means to predict damage positions with greater accuracy than the original RAPID algorithm. Furthermore, the proposed correction does not compromise the computational simplicity of the RAPID algorithm, which is one of its key advantages.