A MULTI-SCALE DATA FUSION METHOD FOR DAMAGE DETECTION OF ROD FASTENING ROTOR IN MODAL STRAIN ENERGY

摘要

A new methodology is proposed for damage detection of rod fastening rotor in gas turbine. Rod fastening rotor is a vibration sensitive structure that exhibit complex and multimodal vibration, it can show some characteristics of vibration when suffered local damage. Due to this fact, the vibration-based method could face a challenge when used for damage detection in these structures. The proposed methodology applies multi-scale space theory and data fusion approach to detect the damage from changes in modal strain energy (MSE). The multi-scale space theory is utilized to cope with the measurement noise, which is inevitable in the process of actual measurement. Based on the multi-scale space data, the proposed methodology finally uses Dempster-Shafer's evidence theory to detect and locate single and multiple damage. The effectiveness of the methodology is analytically verified using two rod fastening rotor with various types of damage scenarios. The analytical results demonstrate that the proposed methodology has superior noise tolerant ability as well as damage detectability, with knowledge of neither the material properties nor boundary conditions. The proposed methodology can make a contribution to ensure safety and performance of gas turbines which play an important role in the power systems.