On the parameters of a tension connection that determine the stability during assembly of thin-walled cylindrical parts

Background. The object of the study is a set of design and technological solutions that determine the stability during assembly with tension of thin-walled cylindrical parts. The subject of the study is the interrelated parameters of the actual contact area and the specific friction force. The purpose of the work is the theoretical determination of the parameters that determine the criteria for stability during assembly (using the Mises formula) and the factors that contribute to the reduction of the friction force during assembly. Materials and methods. Research of the assembly process of thin-walled cylindrical parts assembled with tension using the Mises formula. The specificity of the interaction of the connection parts during assembly is shown and the interrelated parameters of the actual contact area and friction force that affect the stability of thin-walled parts during assembly are determined. Results. The shortcomings of information in the design of thin-walled joints in terms of stability are noted, which, as a rule, lead to the complication of assembly technology. A definition of the critical contact pressure in a joint during assembly using the well-known Mises formula is proposed. The issues of assembling a joint with tension under the influence of a press and the nature of the interaction of the mating surfaces, as well as the issues of forming the actual contact area are considered. The issues of the dual nature of friction and friction force are noted. A number of design and technological solutions are given that contribute to the reduction of friction force. Conclusions. Consideration of stability during assembly of thin-walled cylindrical parts under the influence of a press allows us to note that the determining parameters of critical pressure, in addition to the geometric dimensions of the mating parts, are the actual contact area and the friction force. Control of the actual contact area without reducing operational characteristics is possible by selecting methods for processing mating surfaces. An effective method is to control the friction force, where it is possible to use various technological solutions such as introducing surfactants into the contact zone and applying ultrasonic vibrations.