Justification and selection of the optimal method for draining the field of the “Angrensky” open pit mine in Uzbekistan

An increase in the stability of the slopes of the sides of a quarry or a ledge when using drainage wells with a camouflage cavity is proved in the article by the polarization-optical method. On the obtained diagrams, the distribution of stresses within the massif clearly shows that in an intact massif, the main concentration of stresses is concentrated in the lower edge of the slope, which contributes to the formation of a plane of displacement of the massif and the development of deformations. The presence of a camouflage cavity leads to a redistribution of stresses with the formation of a stress concentration around the camouflage cavity and a significant decrease in the stress concentration in the lower edge of the slope. Thus, we can say that the use of wells with a camouflage cavity not only drains the rocks along the side, but also unloads the border massif, creating favorable conditions for increasing the stability of the drained slope of the side of the open pit.

Photoelastic research of threedimensional problems of fracture mechanics

A polarization-optical method for studying three-dimensional problems of fracture mechanics has been developed. The method was tested to determine the values of stress intensity factors (SIF) for surface cracks in thin plates and thin shells. The data of SIF values for surface cracks of different geometry, which are subjected to different loadings, are obtained. The experimentally obtained values of SIF were compared with those calculated analytically. The efficiency of the proposed technique for solving the corresponding problems of engineering practice is shown.

Study of voltages in inhomogeneous models of supplied combined coatings by the polarization-optica method for monitoring their state

The polarization-optical method for studying stresses in heterogeneous models of combined deposited coatings is considered. The physical foundations of the method and its essence are described. Investigations of the tense state of coatings on heterogeneous models made of viscoelastic materials are presented. Creep curves were obtained, on the basis of which the dependence of specific deformation δ(t) was built, from which the values of the isochron module E2(t) and the price of the strip σ0.2 (t) as a function of time for viscoelastic material were determined.

The study of rolling stock wheels impact on rail switch frogs

Studies of stress distribution across cross sections by polarization-optical method made it possible to propose a relatively simple experimental method of determining contact forces. Experimental determination of contact forces on crossbars of switches is possible by means of sensors located in places of stress concentration (at core base). Analysis of oscillations during impact-pulse loading makes it possible to determine design parameters of the path. Typically, single circuits with four to five degrees of freedom produce quite satisfactory results and may be recommended for the calculated determination of contact forces on the crossbars of the switches.

Особенности поведения доменной структуры кристаллов BaTiO-=SUB=-3-=/SUB=- в процессе термического нагрева и охлаждения-=SUP=-*-=/SUP=-

This paper presents the results of the study of the domain structure of barium titanate crystals in a wide temperature range including the Curie point ( T _C) using the polarization-optical method in the reflected light and the force microscopy of the piezoelectric response. It is shown that a new a–c domain structure forms during cyclic heating of the crystal above T _C and subsequent cooling to the ferroelectric phase. The role of uncompensated charges appeared on the crystal surface during the phase transition and their influence on the formation of the domain structure during cooling are discussed.