Identification of damage in timber I-beams using continuous wavelet transform of deflection measured with digital image correlation

• A method of estimating the measuring and numerical uncertainty of the CWT of beam deflections measured with the DIC technique has been proposed. • Beam damage locations due to the reduction of bending stiffness may be clearly determined by extremes of continuous four vanishing moments wavelet transform only when considering both the CWT measuring and numerical uncertainty. • The proposed method of detecting material defects can be used for the prefabricated timber beam quality control. The article presents a method for detecting damage in timber I-beams based on the continuous wavelet transform (CWT) of their static deflection, measured using the ARAMIS digital image correlation (DIC) system. So far, no detailed uncertainty analysis for this type of identification has been carried out. Filling this gap was the main motivation for the authors to conduct this research. For this purpose, analytical and experimental static deflection CWT analyses were performed for the timber I-beams with softwood flanges and oriented strand board webs, in which local cross-sectional weakenings were artificially introduced for verification purposes. A detailed analysis of the CWT uncertainty resulting from measurement errors and numerical data processing allowed its expression as a function of the beam axis position and the scale parameter. Based on the research, a new methodology was formulated for the diagnostic defect identification in timber beams related to bending stiffness reduction.