One of the main trends shaping the industry today is the development of application methods for various special coatings. Among a large number of coatings, retro-reflective coatings stand out: they are used in a variety of applications throughout the industry. The processes of retro-reflective surface forming have been studied rather thoroughly. The retro-reflective performance depends mainly on structural and optical properties, as well as properties of the radiation source itself. A method was developed to synthesize retro-reflective coatings with specified optical properties using the reflectors in the form of glass microspheres. Retro-reflective performance of the coatings was studied. The paper uses different approaches to microsphere packaging in the bonding layer. It was demonstrated that the half-widths of the scattering patterns of retro-reflective coatings with different structures were quite close, and the reflection maximum of the designed coatings approached the reflection maximum of the commercial “3M” film at the same allowable viewing angles.
The article is devoted to assessing the influence of the parameters of car transmission elements on the nature of the resulting torsional vibrations of the crankshaft of its power plant. As a rule, at present, the study of torsional vibrations of the crankshafts of piston internal combustion engines is carried out separately from the conditions of their operation. Only the operating modes of the engines, the torques of individual cylinders are considered, taking into account the order of operation and the angle between the flashes. If necessary, instead of a linear equivalent torsional circuit, branched circuits are considered that take into account the influence of individual engine mechanisms. Perturbing moments in such schemes occur only on the crank of the crankshaft. Only engine operating modes are considered, which take into account the elements of the car transmission and their influence on the nature of torsional vibrations along the entire length of the driven shaft. The moments of inertia of each transmission element and the stiffness of the equivalent torsional circuit sections are determined. The oscillation equations of the equivalent design scheme are drawn up taking into account the transmission elements. The values of the natural oscillation frequencies are determined by solution of homogeneous differential equations. The influence of the external environment can be estimated by applying perturbing the moment per equivalent mass replacing elements of the undercarriage of the car. Given the large values of the moments of inertia of the elements of transmission and the frequency range of their own vibrations, it is possible to explain the displacement of the amplitude of vibrations and their nodes. The considered technique is of interest for scientific and technical workers, and designers involved in the design of transmission elements for motor vehicles.
Currently, the non-disassembly inspection method of internal combustion engines is one of the most promising methods of assessing their technical condition. This method makes it possible to significantly reduce the intensity of the labour of the diagnostic process and, at the same time, increase its reliability. The paper proposes a method for indiscriminate engine diagnostics based on the Bayes algorithm.
The technological process of obtaining thermally conductive carbon foams based on microspheres and pitches, including the stages of mixing the initial components, pressing the mixture of components, obtaining semi-finished "green" foam, low-temperature carbonization, carbonization, high-temperature heat treatment, pyro-compaction, mechanical processing has been developed. It is shown that the structure of the resulting foam is characterized by a lower content of voids, the layered structure of the walls of microspheres. The obtained values of thermophysical and physical-mechanical characteristics provide the possibility to use the foams for work in extreme conditions
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