Dynamic processes during separation of a tank from the bottom as a result of a fire

The patterns of changes in the parameters of the movement of a part of a tank after separation from the bottom depending on its design parameters and the conditions of its filling were studied. Based on the conducted studies, a mathematical model of the separation process of a part of a tank was formed, which takes into account both geometric and physical nonlinearities of the material. The methods of mathematical modeling, numerical analysis and computer simulation were used for the selected study. Mathematical models allow for an accurate description of the stress-strain state, and numerical methods, in particular finite element and smoothed particle (SPH) methods, provide accurate modeling of the interaction between structural elements and the liquid. Numerical experiments were conducted using the LS-DYNA software package, which made it possible to determine the main parameters of the separation process, such as the maximum stresses in the welded joint zone and the distribution of deformations in the tank material. The results of numerical modeling showed that the main destruction occurs precisely in welded joints, due to the lower strength of the seam compared to the main tank material. This is consistent with the experimental data obtained in laboratory conditions. For a more detailed analysis, a full factorial experiment and regression analysis were conducted, which allowed us to identify the key factors that affect the separation process and establish empirical relationships between the load, material and geometry parameters of the samples. The constructed regression model demonstrates a high correlation between the selected factors and the separation parameters of the tank. The results obtained can be used to predict the behavior of steel tanks during a fire and develop recommendations to improve their safety and strength, taking into account the conditions of real operational loads.