GRSGMD and Its Application to Impact Source Localization Based on UGW

Impact damage localization is crucial in aircraft structural health monitoring. The integration of ultrasonic-guided waves (UGWs) and piezoelectric sensors offers a promising solution for monitoring aircraft structures. However, the challenge lies in the UGW signals generated by external impacts on plate structures, characterized by significant background noise, wide frequency bandwidth, multimodal interference, and inherent frequency dispersion. These complexities hinder the direct extraction of characteristic signals for impact localization in both time and frequency domains. Impact-induced UGW signals typically exhibit Gaussian amplitude-modulated and frequency-modulated (AM–FM) characteristics. Addressing this challenge, this article introduces the Gaussian reconstructed symplectic geometry mode decomposition (GRSGMD) method. GRSGMD combines power spectral density analysis and the Gaussian mixed-model clustering algorithm, to improve the discriminant function of the symmetric geometry component (SGC). This study investigates the decomposition performance and noise robustness of GRSGMD through simulated impact-induced UGW signals. Based on the adaptively extracted dominant energy narrowband of impact-induced UGW using GRSGMD, an impact source localization method is proposed, and verification experiments on aluminum plate impact localization are conducted. The results show that the GRSGMD method can effectively and adaptively extract the dominant energy narrowband of impact-induced UGW. The dominant energy narrowband of low-speed impact-induced UGW corresponds to the
${A}_{{0}}$
mode Lamb wave. The experimental results for impact source localization using GRSGMD align well with actual positions. The research findings contribute to providing an efficient and feasible signal processing method for impact monitoring based on UGW.