The problem of DEM contact models choice is described in the article. An analysis of the input data calibration, including a choosing the contact model, is performed. The main theoretical positions of the most popular models are considered, their comparison is made on the basis of a specially designed stand. Description and justification of the designed stand are considered. The analysis of the obtained results is carried out. Recommendations on the choice of the DEM contact model are given. The results show that it is time-efficient to use non-linear contact model for future model calibration.

The paper discusses the method of identifying the technical condition of induction motors by classifying the energy data coming from the main common power bus. The work shows the simulation results of induction motor operation. The correlation between occurring defects and current diagrams is presented. The developed simulation model is demonstrated. The general algorithm for conducting experiments is described. Five different experiments to develop an algorithm for the classification are conducted: determination of the motors number in operation with different power; determination of the motors number in operation with equal power; determination of the mode and load of induction electric motor; determination of the fault and its magnitude with regard to operation and load of induction motor; determination of the fault and its magnitude with regard to operation and load of induction motor with regard to non-linear load in the flow. The article also presents an algorithm for preprocessing data to solve the classification problem. In addition, the classification results are shown and recommendations for testing and using the classification algorithm on a real object are made.

This paper carries out the research on the continental mining of solid minerals and on the search of the alternative solutions of raw material’s procurement for leading industries. A value of conducting underwater operations for extraction of shelf zone’s ferromanganese nodules is specified. Schematic diagram of conducting mining operations is submitted. The construction of a mining complex for mining ferromanganese nodules of the Baltic Sea with the possibility of its separation partial enrichment on the seabed during the process of production is proposed. An analytical model of the system with bottom device and flexible traction element is given. The interaction between a flexible traction element and a bottom-mining unit allows to define the character of relative motion and also to describe the position of the flexible traction element as it moves in the aquatic environment. Specific conditions for steady operation of the complex for its inseparable moving on a seabed are presented.