%0 Journal Article %T Measuring Crack-type Damage Features in Thin-walled ‎Composite Beams using De-noising and a 2D Continuous Wavelet ‎Transform of Mode Shapes %J Journal of Applied and Computational Mechanics %I Shahid Chamran University of Ahvaz %Z 2383-4536 %A Pacheco-Chérrez, Josué %A Cárdenas, Diego %A Probst, Oliver %D 2021 %\ 01/01/2021 %V 7 %N 1 %P 355-371 %! Measuring Crack-type Damage Features in Thin-walled ‎Composite Beams using De-noising and a 2D Continuous Wavelet ‎Transform of Mode Shapes %K modal analysis %K damage detection %K damage assessment %K 2D curve fitting‎ %R 10.22055/jacm.2020.35156.2580 %X A new method is described, allowing to locate and also measure the length and orientation of crack-type damage features in thin-walled composite beams (TWCB), a capability not previously reported. The method is based on a modal-analysis technique and is shown to work on a hollow composite beam, going beyond previous work limited to simple beams and plates. The method is shown to be capable to function down to signal-to-noise ratios (SNR) of about 15, corresponding to far noisier conditions than in most previous work. This capability is achieved by a combination of wavelet de-noising and the use of a 2D Continuous Wavelet Transform (CWT), applied to two modal analysis metrics, COMAC and Mode Shape Differences (MSD). The length and orientation of the crack can be determined accurately using a 2D curve fitting approach. Using either COMAC or MSD produces reliable results, but MSD is found to be somewhat more noise-tolerant. The new method is believed to be useful for the measurement of damage features in a variety of thin-walled composite beams such as aircraft wings and wind turbine blades, among others. %U https://jacm.scu.ac.ir/article_16032_9c33c1e1db1f0e63ddc82a6131823cdd.pdf