Proceedings of the International scientific and practical conference ― Cambridge Science and Education Conference‖ (February 23-25, 2026) / Publisher website: www.naukainfo.com. – Cambridge, United Kingdom, 2026. - 289 p.

85 rocket and space technology [1, 2, 3, 5]. It should be noted that modern engineering methods and finite- element analysis application packages provide ample opportunities for the effective use of a wide range of tools of this effective approach, which allows obtaining sufficiently reliable calculation results [4, 7]. At the same time, incorrect use of these capabilities, in particular, when choosing a calculation scheme, formulating conditions for interaction with other substructures, insufficient accuracy in taking into account external influences, etc. can significantly affect the calculation results [6]. The presented work demonstrates that to obtain reliable results of calculating the strength of bolted connections elements of compartments, the correct choice of the calculation scheme is extremely important. The connection of the launch vehicle compartments is carried out by using bolted connections of the end frames of individual compartments. The structural diagrams of such connections have the following form (Fig. 1), where 1 is marked – fuel tank; 2 – tail compartment; 3 – oxidizer tank; 4 – second stage; 5 – bolt; 6 – spring washer; 7 – oxidizer tank frame; 8 – unloading sleeve. а ) b ) c ) Fig. 1. Typical bolted connections of the launch vehicle compartments: a ) connection of the tail compartment body with the fuel tank; b) butt connection of the oxidizer and fuel tanks; c) structural diagram of the connection of the stages