Volume 39, Nº 8 (2019)

Neural-network models used in the development of digital twins for production equipment are considered. Such a model of the dynamic stability of cutting is assessed. A spectrogram showing the vibrational amplitude and frequency of the elastic system in a CNC machine tool is presented. The fractional dimensionality of the corresponding attractors is determined.

Hydrodynamic models are considered for thrust bearings with a profile adapted to the frictional conditions, when operating in incompressible electrically conducting lubricant. The basic operational characteristics of a bearing, with deformation of the frictional pair’s supporting system, are derived on the basis of the equation of motion of the material in the working gap, the continuity equation, and the Darcy and Lamé equations for a thin layer.

A method of comparing the geometry of 3D models on the basis of engineering experience with other models is proposed. The method is embodied in software.

The use of information theory to formulate an informational model of the change in state of mechanical systems is considered. By that means, models of the change in state of system components may be developed for different operating conditions. In regions of the system’s state space corresponding to critical values, the probability of a fault may be determined.

The electromagnetic calculation of electromechanical converters in guaranteed power-supply systems for drives of machine tools and manufacturing equipment is outlined.

In the erosion-free zone that appears during high-amplitude ultrasound treatment, the useful work is mainly performed by cavitational clusters. In the absence of collapse, the clusters grow and produce small-scale turbulence. As shown in the present work, cavitational clusters may be activated by the additional acoustic pressure arising when a low-amplitude source is coaxial with the high-amplitude source.

Computer engineering permits the creation of models closely matching actual processes and vehicle designs. Production costs may be significantly reduced, while additive technologies permit customized production, with minimal expenditure of time and materials in development and prototyping. Such technologies may expediently be used in digital design of vehicles, taking account of the complete product life cycle.

The conversion of diesel engines to gas and gas–diesel cycles during the production process is analyzed. The requirements for conversion to natural-gas operation are presented. The power, efficiency, and environmental impact of diesel engines, natural-gas engines, and gas–diesel engines are compared.