Experimental validation of a new statistical process control feature for damage detection

A novel statistical process control-based method for damage detection in cantilever-like structures is presented in this paper . It is based on time-domain data obtained from the free vibrations of the first mode of the structure, measured at only one point. The concept of signal length is introduced here as a feature for statistical process control. A statistical model consistent with extreme value theory is fitted to the operational data and used to establish control limits. A strategy based on controlling runs is adopted to increase the sensitivity of the detection. The procedure was applied to a four-storey steel frame, which was subjected in turn to mass and stiffness modifications by adding masses or loosening bolts in a beam–column connection. The results were successful; the proposed procedure was able to detect an increase of 0.04% of the total mass of the frame and loosening of one out of 152 bolts.