Moscow Polytechnic University, Moscow, Russia

D. A. Gnevashev, Cand. Eng., Head of the Dept. of Materials Forming and Additive Technologies, e-mail: dengnevashev@mail.ru
Sh. F. Orudzhev, Master's Student, Dept. of Materials Forming and Additive Technologies, e-mail: shamil-orudzhev@rambler.ru

Bending sheet metal on sheet-bending machines is one of the most common metalworking methods, which makes it possible to produce spatial parts with permanent connections without welding two or more elements located in different planes. In this case, the bend itself represents a rounded corner, the radius of which should not be less than the permissible value. During the bending process, the metal sheet on the bending line is deformed with tension on the outer surface and compression on the inner side of the corner. This changes the crystal lattice structure and can lead to its destruction in places of overstress. Such overstress due to strong bending of the sheet leads to its fracture along the fold line. Thus, for safe bending of sheet metal, it is necessary to select a value for the bending radius such that tension outside the corner and compression inside it do not lead to critical overstress, and the metal itself retains its strength on the bend. Compliance with the minimum radius when bending metal sheets leads to the need to take it into account when choosing the length of the sheet blank. The bending process is also influenced by the shape and design of the bending tool. The possibility of multi-point bending was studied using the example of a sheet product made of 08kp material under conditions of a shortage of bending tools. The features of multi-point bending of long products on modern equipment ar eshown and the process of ensuring the required accuracy of their parameters as a whole, including the corresponding stages of the product life cycle, is presented. Using mathematical modeling, a study was carried out on the bending of long products under conditions of a shortage of bending tools, and the data obtained were confirmed by practical work.

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