Damage detection of fastener loosening of aircraft stiffened panel by auto correlation analysis

An approach to detect structural damage using auto correlation function was proposed. It was theoretically proved that the value of normalized auto correlation function of acceleration response at zero point of time axis depends only on the modal parameters of the structure, which is used to get the damage index to then locate the damage. The feasibility and the effectiveness of the proposed method were verified by damage detection experiments for the fastener loosening of aircraft stiffened panel under white noise excitation. The results of the damage detection experiments show that the proposed method, in which only the acceleration response is needed, is suitable for real time detection of the fastener loosening.