PSI - Issue 17

H. Lopes et al. / Procedia Structural Integrity 17 (2019) 971–978 Lopes et al./ Structural Integrity Procedia 00 (2019) 000 – 000 7 where is the wavelength of the laser light beam, Δ and Δ are the shearing amount in and direction, respectively. In the book chapter by dos Santos and Lopes (2018), the interested reader can find more information about shearography and its applications. 977

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(c) Fig. 5. Experimental modal rotations: (a) phase maps, (b) filtered phase maps, and (c) 3D representation of modal rotations for the direction, corresponding to the first, ninth and fourteenth natural frequencies.

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(c) Fig. 6. Experimental modal rotations: (a) phase maps, (b) filtered phase maps, and (c) 3D representation of modal rotations for the direction, corresponding to the first, ninth and fourteenth natural frequencies. Figures 5 and 6 present the unfiltered phase maps, the filtered phase maps and the modal rotations for, respectively, the and directions, corresponding to the first, ninth and fourteenth natural frequencies. The spatial resolution for