Vol 39, No 4 (2019)

The possibility of predicting the fatigue limit of surface-hardened steel 20 with semicircular notches is considered: (1) on the basis of the residual stress at the surface of the cut; (2) on the basis of the integral mean residual stress over the thickness of the surface layer in the most hazardous cross section, which is equal to the critical depth for fatigue-crack propagation. The second approach proves more accurate. Experiments confirm that the critical depth for fatigue-crack propagation depends on the size of the most hazardous cross section.

Forced vibrations of a cylinder with a displaced center of gravity on a rigid base vibrating horizontally (perpendicular to the generatrix of the cylindrical surface) are investigated. At the contact point between the cylindrical surface and the base, dry friction is assumed. The problem is solved by the Bubnov–Galerkin method. The results are expressed as amplitude–frequency characteristics.

A cyclic test method for the fatigue strength of metals is proposed. In this method, fatigue curves characterizing the stress dependence of the number of cycles to failure are plotted and statistically described. The number of cycles to failure is described by a Weibull distribution, using the lowest guaranteed values.

A new cap design eliminates thermal disruptions in the destruction of sand–polymer shaping mandrels when manufacturing polymer composite parts.

A mathematical model is developed for the drawing of an anisotropic hardening material without wall thinning, in the case of radial-matrix clamping. For sheets of various materials, the forces required and the associated damage are investigated as a function of the drawing coefficient, the rounding radius of the matrix, the frictional conditions at tool–workpiece contact, and the clamping materials.

In manufacturing, a staff development strategy is necessary on the brink of the Fourth Industrial Revolution. The components of this strategy are considered in detail. New specialties and organizational models arising from the Fourth Industrial Revolution are noted. Proposals include the creation of a participatory organization, a new incentive system, and the cultivation of electronic leadership.

An improved hobbing tool for the finishing of involute-gear teeth is proposed.

The influence of the cutting parameters and insert geometry on the inclination of the conditional shear plane is studied, analytically and by the finite-element method, in the turning of Niresist iron. The corresponding formulas are derived.

The prospects for digital technology in the aviation industry are assessed in the present work. The Russian state program on the digital economy is assessed. Its key features are outlined, including selective competition between aviation enterprises. Special attention is paid to the new paradigm of digital design and simulation of next-generation products.