Vol 39, No 3 (2019)

The failure of threaded joints between composites with 4DL reinforcement is analyzed. A formula is proposed for estimating the carrying capacity of a threaded joint at the design stage.

The effectiveness of vibration-damping coatings is assessed by simulation. The experimental characteristics of the coatings are presented. An algorithm is proposed for assessment of the expected dynamic parameters of structures as a function of their shape and the characteristics of the vibration-damping materials.

The passive suspension of a six-wheeled self-propelled chassis is analyzed in terms of the influence of its kinematic and geometric parameters on the configuration, cross-country ability, and static stability of low-speed autonomous planetary rovers. The results of the synthesis of a new suspension scheme for a four-wheeled chassis are presented.

The factors that significantly affect the wear resistance of components in the cylinder–piston group are established by experiment and rank correlation. In the operation of the cylinder–piston group, vibration greatly intensifies the wear.

The design of tools with adjustable geometry is analyzed. A design is proposed for a boring tool with a replaceable polyhedral insert in which the lead angle may be varied. This design permits the machining of blind and through holes in the workpiece with the same cutter.

The influence of the conditions of electrospark machining on the structural changes and roughness of the machined surfaces and hence on their wear resistance is studied experimentally. After electrospark machining of 38Х2Н2МА steel with the minimum parameters, the roughness of the machined surface is found to be minimal. However, the depth of the modified layer (the zone of diminished microhardness) is a maximum. When using the maximum electrospark parameters, the roughness of the machined surface is a maximum, whereas the depth of the modified layer is a minimum. The zone of diminished microhardness affects the wear resistance of the working surfaces and the working life of the part as a whole. In specifying the conditions of electrospark machining, large currents I (А) must be used, or else subsequent operations will be required to remove the modified layer from the machined surface.

The temperature dependence of the electromagnetic properties of hard tool alloys is studied experimentally. Temperature intervals corresponding to maximum alloy performance are identified. A method is proposed for determining the maximum-performance temperature of hard-alloy cutting inserts from the temperature dependence of the electromagnetic properties.

The onset of a new industrial revolution calls for certain strategic changes. Transformations in the aviation industry are discussed. A formula for the flight efficiency is presented. Composites that increase the flight efficiency are considered. Strategies for the education of aviation specialists in this era are outlined. The applicability of these strategies is illustrated for a course on strategic management. A new index of educational efficiency is proposed, taking account of new competencies appropriate to changing times. Results obtained by means of the proposed model are presented. The role of learning organizations at a time of change is analyzed.

The deficiencies of existing standard iron and nickel samples for calibration by means of X-ray diffraction are noted. These standards cannot be used in calibration by magnetic noise recording. A new calibration method based on X-ray diffraction is proposed, using plane samples of the material employed in the manufacture of the actual structures. Theoretical analysis provides the basis for the development of null standards in which a plane sample is deformed by pure flexure or in a cantilever-beam configuration.