PSI - Issue 59

Leonid Lobanov et al. / Procedia Structural Integrity 59 (2024) 43–49 Leonid Lobanov et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Derived examination results allowed creating a database and more precisely determining the peculiarities related to defect detection and identification. With this purpose, during the performance of technical diagnostics of the TV tower elements, visual and measurement inspection of the structure using DJI AIR 2S UAV with a built-in camera with up to 4K Ultra HD resolution was additionally applied, in parallel with the generally accepted visual inspection method. During work performance, more than 470 defects areas located on 189 elements were detected. Total number of examined structure elements was approximately 720 pcs. Depending on the energy of fragment impact on the tower structure element wall, the following types of damages were determined for their further analysis:  Complete penetration of a fragment through one pipe wall without any impact or with plastic deformation of the other wall, Fig. 2;  Complete penetration of a fragment through two pipe walls (shot through), Fig. 3;  Partial penetration of a fragment through one pipe wall to different depth (crater);  Dents in the pipe wall and element deformation under the impact of the fragments and shock wave;  Breaking of an element or its fastening unit;  Presence of cracks in the places of fragment impact and in element bracing units;

 Breaking of vibration dampers between the elements;  Breaking of anticorrosion protection of element surface.

Fig. 2. Example of a partial or complete penetration of a fragment into the wall of girder pipe of support leg “ А ” .

Fig. 3. Typical condition of the other wall of pipe element in the zone, where the fragment flew out with traces of surface plastic deformation.