Tula State University, Tula, Russia:

V. D. Kukhar, Dr. Eng., Prof., Head of the Dept. of Theoretical Mechanics
V. A. Korotkov, Cand. Eng., Associate Prof., Dept. of Mechanics of Plastic Form Change
S. S. Yakovlev, Postgraduate Student, e-mail: yakovlev-ss-science@yandex.ru
A. A. Shishkina, Undergraduate Student

A new method for corrugating the inner surface of shells has been developed, which consists in local plastic forming with a tool of limited length. On the basis of previous theoretical studies of the process of applying the corrugation by computer simulation, experimental studies of the corrugation of the inner surface of the shell were carried out using a newly developed experimental stamp and a hydraulic testing machine. The processes of applying corrugations on a steel billet, as well as removing the finished semi-finished product from the tool, were studied. An assessment of the influence of the shape of the lead-in part of working mandrels, with the help of which the corrugation is carried out, has been taken, and rational ones are established with respect to the resulting quality of the product. The assessment of corrugation force and product removal was taken and compared with the results of computer simulation. Also, the work defines the forces required to form one corrugation, since the process is local. An image of the experimental stamp designed specifically for studying the corrugation of the inner surface of a cylindrical shell is shown, as well as blanks before shape change and final products after corrugation are illustrated. It has been established that computer simulation adequately reflects the processes of corrugation, which is confirmed by a comparative analysis of theoretical and experimental data. Conclusions are drawn about the possibility of using the developed method of local shaping for corrugation of the inner surface of a steel cylindrical shell.

The study was supported by a grant from the Russian Science Foundation No. 22-29-20212, https://rscf.ru/project/22-29-20212/, and the Government of the Tula Region.

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