EVALUATION OF VIBRATION EFFECTS OF BULKY ELEMENTS ON THE CYLINDRICAL PART OF TANK CAR BOILERS BASED ON SHELL THEORY

Abstract

The problems related to the vibration effects of bulky elements on the cylindrical shell of tank car boilers are considered. To do this, an approach based on the shell theory is proposed. Donnell equations are used to define the loading during vibrations. Equations based on the theories of depressed cylindrical shells and on the polytechnic theory of shells are used. In order to confirm the reliability of the results obtained according to the proposed approach comparative analysis is performed. The rigidity of the attached cylindrical shell is estimated, for which experimental values of deformation under the local load are obtained. The results of calculations for the local single load of a closed cylindrical shell by means of finite element method (FEM) are given. These results show a satisfactory conformity with the data obtained experimentally (based on calculations). Using the proposed technique, the authors evaluated rigidity of the boiler cylindrical part where bulky elements are installed and this makes it possible to define the values of natural frequencies and the level of dynamic addition for various design parameters. Geometrics for tetra axial and eight axial tank cars are used as examples. Additionally, gain-frequency characteristics of deformations, accelerations and dynamic coefficients in the places of bulky elements are presented. Study results can be used to improve the design and the conditions for using tank car boilers.