THE EFFECT OF EXTERNAL AND INTERNAL PRESSURE ON THE STIFFNESS OF BOILER SHELLS OF THE TANK CAR

The paper studies the influence of external and internal overpressure on the stiffness characteristics of boiler shells of tank cars, which play a key role in the car design, ensuring the safety of freights such as oil, oil products, bulk cargoes, gas and chemicals. The research is aimed at developing a scientific approach to assess the effect of various pressures on the frequency characteristics of shells and their stability, which is critically important to ensure their reliability and safety. Mathematical expressions are developed to determine the frequency of natural oscillations and the critical pressure at which the stability of the boiler shell is lost. The numerical analysis performed using the finite element method confirms the adequacy and accuracy of the proposed models. The results of the study show that a decrease in internal pressure leads to a decrease in the stiffness of the shell and, accordingly, the frequencies of natural oscillations, which can cause a transition to an unstable state. At the same time, an increase in internal pressure contributes to an increase in stiffness and oscillation frequencies. These conclusions are of great importance for the design and operation of tank cars, as they allow to take into account potential risks and develop safer and more effective design solutions. The data obtained can contribute to improving the safety of cargo transportation, including dangerous freights.