An impact localization method for curved composite structures based on stress waves

Timely and accurate monitoring of impacts from flying birds, hail, and other objects is of great significance for aircraft. The impact monitoring based on acoustic emission has the characteristics of wide range and high accuracy, and the stress waves generated by the impact represent important information. However, many composite curved structures of aircraft have the characteristic of curvature changes and the anisotropy of their materials, which affect the accuracy of impact positioning. The study develops an impact localization method for composite curved structures based on stress waves. First, a sensor array adapted to the curved surface is designed. Next, several signal features are extracted and selected, focusing on those minimally affected by material anisotropy and the curved structure. Finally, an improved weighted centroid localization method was implemented by utilizing the fused values of these features, enabling a two-step localization approach in which the region is determined first and the impact location is subsequently pinpointed. Experiments were conducted on composite fan blades of aircraft engines, and the results demonstrated that the proposed method holds practical engineering value for impact monitoring in composite curved structures.