The article presents the results of research on antifriction coatings for use on die made of aluminum alloys. The expediency of using antifriction coatings to reduce friction when stretch-forming of double curvature shells is justified. To substantiate this, we performed numerical modeling of the skin-tight forming process in the «LS-dyna» CAE system. According to the results of modeling, the following relationship is observed: the lower the coefficient of friction, the more evenly distributed the thinning deformations over the thickness of the blank in stretch-forming. Test modes for determining the coefficient of friction on the MTU-01 friction machine and methods for obtaining other basic functional and technological properties of antifriction coatings are described. The antifriction and technological properties of coatings, such as the coefficient of friction, adhesion, wear resistance, conditional hardness, the time and temperature of polymerization of the coating are determined.
The paper presents a comprehensive study of the surfaces of plastic samples (90% polysulfone (PSU) + 10% polycarbonate (PC)) modified with the help of an ultrasonic resonator to reduce friction in contact between the material of aluminum skins and a covering puncheon. Comparative characteristics of surfaces have been obtained, such as: microhardness, coefficient of friction and wear resistance in contact with wrought aluminum alloy D16T.
The paper is devoted to the assessment of the possibility to use a new design of a stretch die made of plastics used for fused deposition modeling (FDM) 3 D printing. Studies were conducted to assess the stress-strain state of a stretch die, from the normal pressure of a deforming sheet blank in a NASTRAN solver, using the finite element method. The convergence assessment of the simulation results was carried out for different quantities and corresponding sizes of finite elements. The optimal thicknesses of the hollow structure of the stretch die were determined by step-by-step calculations of its stress-strain state for acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PETG). On the basis of the conducted studies, a general algorithm was developed for the structural design of stretch dies made of plastics used for fused deposition modeling (FDM) printing.
Тенденции развития науки и образования guidelines for assessing satisfaction and improving the quality of services provided. In our opinion, special attention should be paid to sections of the standard. ISO 9000 is related to customer requirements because passengers are direct consumers of the service. Therefore, in the system of long-distance transportation, mechanisms for assessing customer satisfaction should be developed and applied.
The methods for manufacturing of the frames of the aircraft are analyzed. The most optimal technological route for the manufacture of frames is selected. The process of stretch bending is considered, the problems arising during its implementation are shown. The ways for improving of the stretch bending process described in open sources are analyzed. The parameters necessary for the development of an adaptive control system for the stretch bending process are determined.
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