Keyword: «harmonic analysis»

The features of the interaction in the wheel-rail system are considered, taking into account the design factors and the railway track state and their influence on the contact fatigue life of rails. Models of the railway track have been developed, including the superstructure and substructure, along with other infrastructure in the railway zone, and allowing to study the properties and performance capability of the track in connection with the prospect of the increase in axle loads and freight traffic in certain sections of operation, as well as in connection with state deterioration when stiffness of the track superstructure and substructure is changed due to the natural and climatic conditions of the North.

A method for assessing the stress-strain state (SSS) of a railway track in the conditions of the Far North and Siberia is proposed for consideration, which consists in the fact that, in accordance with the structure of the track, three-dimensional finite element (FE) models of the studied section of the railway track with the infrastructure adjacent to it are created, harmonic loading of FE models is carried out, the stiffness of the elements of which corresponds to the stiffness of the frozen and thawed section of the railway track with the adjacent infrastructure, the results of the harmonic responses of the loaded three-dimensional finite element models are used to determine the frequency range of the experimentally measured SSS parameters.

With the help of harmonic analysis of such multiscale finite element models of cubic cells with point mass elements contained in the middle inside, the possibility of physical substantiation of phase transitions in solids at micro- and mesolevels of deformation is shown.

A methodology for studying the stress-strain state of track sections has been developed. This methodology utilizes both static and modal analysis, as well as harmonic analysis, using the finite element method. The feasibility of comparative analysis of changes in the dynamic parameters of the stress-strain state of track elements at different temperatures is demonstrated.

We propose a method for solving problems of large-scale mineral extraction by creating four simplified, scaled-down (20,000 times smaller) finite element models of the Earth, each containing a core, mantle, and a relatively thin, continuous crust. In the second model, a spherical excavation extending to the mid-depth of the Earth's crust is made near the North Pole. In the third model, a similar excavation is made near the equator. In the fourth model, two such excavations are made near the pole and the equator. These excavations simulate the global extraction of raw materials at these locations. Static, modal, and harmonic analyses of the models are then conducted, and the impact of global resource extraction on changes in the static and dynamic strength characteristics of the models under consideration is assessed.