stress

Research and mathematical modeling of fractional-differential rheological models

Deformation processes in media with fractal structure have been studied. At present, research on the construction of mathematical methods and models of interconnected deformation-relaxation and heatmass transfer processes in environments with a fractal structure is at an early stage. There are a number of unsolved problems, in particular, the problem of correct and physically meaningful setting of initial and boundary conditions for nonlocal mathematical models of nonequilibrium processes in environments with fractal structure remains unsolved.

Optimization of the structures by the static strength and the frequency characteristics

Problems of determination of optimal geometric and constructive parameters of long-length structures are presented. For example, a longitudinal profile of a complicated section is adopted, its components of the stress state and its own oscillation frequencies are determined. The choice of optimal profile parameters is made for the implementation of structures with minimum equivalent stresses, as well as for ensuring maximum dynamic stiffness.

Improved calculation and strength of thermowells during operation

Accurate evaluation of possible safe operation of thermowells essentially depends on the accuracy of the maximum stresses in them during operation. These stresses are generally determined from simple engineering formulas for bulk of canonical shape, mostly cylindrical shells or beams for the relevant boundary conditions. Thus the general solution is obtained step by step. First the tangential stresses are obtained from relations for cylinder subjected to external pressure.

Investigation of the Carbide-tipped Tool Wear Hardened by Method of Aerodynamic Impact

Theoretical calculations and experimental studies of the influence of wear on the cutting process and the precision parameters of machining by hard alloys during milling are described in the article. The method of aerodynamic hardening is designed to increase the durability of tools, which are heterogeneous compositions of tungsten carbides, titanium and tantalum with cobalt ligature operating under severe process conditions with varying impact loads.

Formation Residual Stresses and Their Dependence on Technological Parameters of Process of Machining Parts

There are considered the technological ability to manage residual stress during machining by correcting the distorted structure of the treated surface det-lei new vector machines cutting speed for roughing and finishing operations processing.

The Cenozoic stress/deformation fields of the Donets coal basin and their probable sources

The periodicity, dynamics and kinematics of unadequately studied Cenozoic activities in the Donets intraplate foldbelt (“the Donbass”) and in its neighbourhood were considered. It have been demonstrated that two independent orogenies divided by a tectonic pause in the Eocene-Oligocene took places there, the Laramic one (the terminal Maestrichtian – Paleocene) of an early Alpine tectonic epochs and conventiolly neotectonic one (Early Miocene – Quaternary) of a late Alpine epoch.

The dislocations on the surface of the Earth as a result of the strong earthquakes in the Western Tien-Shan

Purpose. The aim of the research is to estimate parameters for seismic dislocations, for example of strong earthquakes in the Turan platform and adjacent mountainous part of Western Tien-Shan, as well as identifying the relationship between the magnitudes and lengths of breaks for pleistoseist zones. Methodology.