FEATURES OF THE STRESS-DEFORMED STATE OF VERTICAL CYLINDRICAL TANKS UNDER EXTERNAL PRESSURE

Abstract

The paper investigates the features of the stress-deformed state of cylindrical shells under wind pressure, taking into account its actual distribution on cylindrical structures. The purpose of the work is to obtain a qualitative picture of the distribution of stresses and deformations in the cylindrical wall of the tank under wind load, to determine the effect of wind load on both the strength and stability of the tank. Practical significance. It is known that the stresses caused by the action of the wind load, due to their small value, are safe from the point of view of strength, at the same time, obtaining quantitative values of the stress-deformed state main components of the tank under wind load has a certain practical significance. The task is to solve the problem of deformation of the cylindrical shell under external uneven pressure of the wind type. Content of research. The solution of the deformation problem was performed in a linear formulation for cylindrical shells with geometric parameters corresponding to the geometric parameters of vertical tanks with a volume of 1,000…30,000 m³. The solution of the problem was carried out for several loads of the shell with wind pressure of different intensity q = (0,2…1,2) q_crw. Such formulation of the problem made it possible to investigate the features of the stress-deformed state of cylindrical shells under wind pressure both at small values of the external load and at pressure values close to the critical ones, which is important from the standpoint of shell stability. Conclusions. The static calculation of the shells under wind pressure showed that membrane stresses in the annular direction prevail. Membrane stresses in the meridional direction are the second largest. The distribution of these stresses along the perimeter of the shell corresponds to the wind pressure plot. The main feature of the bending stress graphs is their wave character along the perimeter of the shell. Plots of radial displacements w and deformed shells also have a wave character. The size of such wave deviations is insignificant, but their length is close to the length of the waves of the shell protrusion when it loses its stability. Thus, the process of deformation of cylindrical shells under wind pressure is generally stable. The wind load itself is safe from the strength point of view. However, the obtained nature of the deformation, namely the wave deviations of the surface of the shell, can significantly affect the stability of the shell, which requires additional research.