Damage detection based on output-only measurements using cepstrum analysis and a baseline-free frequency response function curvature method

Low-severity multiple damage detection relies on sensing minute deviations in the vibrational or dynamical characteristics of structure. The problem becomes complicated when reference profile healthy structure and corresponding input excitation, is unavailable as frequently experienced real-life scenarios. Detection methods that require neither undamaged (baseline-free) nor excitation information (output-only) constitute state-of-art structural health monitoring. Unfortunately, their efficacy ultimately limited by non-ideal masking crucial attributes system response such resonant frequency peaks beyond first (few) natural frequency(ies) which can better resolve issue detection. This study presents an improved function curvature method both baseline-free output-only. It employs cepstrum technique to eliminate [Formula: see text] decay higher resonance caused temporal spread real impulse excitation. Long-pass liftering screens out bulk low-frequency sensor noise along with With more visible peaks, purified functions (regenerated functions) register finer deviation from estimated baseline yield accurate index profile. simulation experimental results beam show proposed successfully locate damages severity low 5%.