Study of Liquid Cargo Influence on Frequency Characteristics of Tank Wagon Boiler Shell

The article is devoted to the study of the effect of the fill level of liquid cargo on frequency characteristics of the shell of a tank wagon boiler. The study has applied within its framework an approach used to estimate the frequencies and modes of natural oscillations of steel tanks under the influence of seismic loads. This approach assumes considering two components of natural frequencies: pulse and convective ones. To determine the listed frequencies and modes of natural oscillations, the finite element method using FLUID221 acoustic elements was selected. The choice of the method is justified in the previous studies of the authors. Using the selected method, convective natural frequencies of oscillations of the free surface of the liquid and pulsed frequencies of natural oscillations with different fill levels of the tank wagon boiler with liquid cargo were studied. Confirmation of reliability of the results for pulse frequencies of the shell containing the liquid is ensured by consistency with the data obtained by the authors in previous works using the semi-momentless theory of shells.