RESEARCH OF THE PROBLEM OF LOSS OF STABILITY OF CYLINDRICAL THINWALLED STRUCTURES UNDER INTENSE LOCAL TEMPERATURE EXPOSURE

Abstract

Presently, three-dimensional printing technology is developing rapidly. This happens due to the need to create products of complex shape, the production of which by existing standard methods is very difficult and disadvantageous, and sometimes technically impossible. The study aims to investigate the problem of temperature stability of a thin-walled cylindrical structure under unsteady local thermal exposure, simulating the motion of a laser beam spot along one of the ends. To solve the problem, the finite element method was used. Since the geometric areas of calculation were parameterized, then for each set of parameters, its own finite element mesh was used for each type of analysis. A parametric spatial finite element model of cylindrical shell pinched at the bottom end was constructed. The local moving heat flux acts on the opposite side, simulating the movement of a laser beam during the additive formation of a thin-walled element. Numerical solutions of the nonstationary dynamic heat conduction problem were obtained, spatiotemporal temperature dependences were obtained, and solutions of the quasistatic problem of the loss of both local and complete loss of stability of the equilibrium state of the cylinder at various times due to the occurrence of local compressive stresses during intense heating were obtained. The dependences of critical heat flux power corresponding to the loss of stability on the cylinder wall thickness and its height were obtained. The above results can be used as calibration parameters of the process of creating thin-walled structures using additive technologies of Laser Melting class for products that require increased requirements for manufacturing accuracy.