International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The fatigue of metals is a relatively new part of mechanics of destruction. In modern theories to explain the destruction of a material of fatigue is considered that the process begins and flow the basis of generation and accumulation of micro-cracking in the material. To describe this process is by using kinetic diagrams of fatigue. The interest to the theory is a discussion of the process of fatigue of middle level. This article examined the kinetic diagrams of fatigue of middle level and evaluate their parameters by ultrasound measurements.

This work is a continuation of the HUPER development, as in this study hydrophilization was performed by different types of cement (grey cement and medical cement). It was established that alkaline hydroxides in the cement “milk” composition traditionally perform the preselected role of a hydrophilizer. Water was used as a second dispersing component, which can not only homogenize the composition of the prepared composite material. A third component was introduced (water glass), which was studied due to its dispersing role towards the resin/cement/water system. Mechanical strength characteristics (mostly impact characteristics) characterizing the shape, dimensions and integrity of the operational product were studied based on the obtained composition in various proportions of components.

This paper researches the influence of the cutting edge’s geometry and coating on its durability. Four types of edge geometry and two types of coating are studied as well as the influence of abrasive material on production of the chamfer.

Ordinary in the theory of machine elements a deterministic stress conditions are used. In general case there are relationships between “acceptance stress” and “working stress”. In practice the stresses are random values. Therefore the stress conditions have got probabilistic formulation.

In this paper the probabilistic formulation of stress conditions for machine elements are presented.