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The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. Using the inclinometric method, it is possible to determine the deviations of the conductor in space from its equilibrium position. Having restored the geometry of the conductor in the span of an overhead power line, mechanical loads can be determined. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The developed model allows you to determine the arrow of its sag from the period of oscillations of the conductor in the span. The article considers algorithms for calculating the conductor sag arrows for two cases: the conductor suspension points are at the same height; conductor suspension points are at different heights. A theoretical calculation is given for a model of a span overhead power line with an estimate of the sensitivity of the developed model and its error in determining the sag of the conductor. Using the arrow of the conductor sag, you can restore its geometry, and hence the mechanical load of the conductor. Therefore, knowing the initial geometric parameters of the span of the overhead power line and the current period of the conductor’s oscillations, it is possible to examine its current state.

Structural elements of overhead power transmission lines are experiencing both horizontal and vertical loads. Wires and cables are elements of the overhead power line, on which changes in mechanical loads are observed to a greater degree. This occurs due to the change in the tension force of the wire/cable depending on the temperature and the formation of icy-rime deposits on it, as well as fluctuations in wind gusts. The article describes the most common systems and methods for determining the mechanical loads on an overhead power transmission line. A method is proposed for calculating the mechanical loads on an overhead transmission line based on mathematical models of a flexible wire, rope and a model for determining ice deposits on wires, taking into account the rotation of the wire/cable around its axis. A comparison of the improved inclinometry method with the method developed earlier for the case of formation of ice deposits on the S-50 cable has been carried out. A comparison was made on the error in determining the tension of the S-50 ground-wire protection cable using the method developed to control the mechanical parameters of overhead power lines, which takes into account the wire/cable rotation around its axis and the method for determining icy-rime deposits developed earlier. The developed method allows determining the elongation of the wire/cable in the span with one anchor support, as well as the strength of its tension with greater accuracy. However, additional clarification is required due to the influence of the wind, the formation of icy-rime deposits of various shapes, as well as the structural limitations of the wire/cable rotation when attaching it to the support.

Waterproof clothing must remain protective throughout its life. But in the course of operation, waterproofing materials are subjected to mechanical loads of low intensity. Under the influence of stretching, compression and bending, fatigue phenomena in the structure of the material accumulate, the bonds between the elements of the structure are weakened, and the material is destroyed in the places of the most frequent application of loads. The article is devoted to the study of the structure of waterproofing materials with a polyetherurethane membrane and the evaluation of the effect of mechanical operating loads on the parameters of the structure of materials of various types. Analysis of the results of the study will help manufacturers of clothing from membrane materials to implement a sound selection of materials, increasing the durability of products.

It is shown that the crucial role on efficiency of functioning of transport, namely quality of rendering of services on transportations of passengers and loads, is rendered by systems of objective monitoring. The perspective which is dictated by existence of a contradiction comes to light: on the one hand this requirement concerning increase of efficiency and reliability of provision of video information that carries to increase in their volumes, and on the other hand limited carrying capacities and high-speed performance of remote sites of collection of video information that leads to the limited productivity of a technological component. Reasons for option of increase of a compression ratio of a vi-deoinformatsionny flow in infocommunication systems in the conditions of support of the given reliability of information on the basis of abbreviation of temporal redundance on the basis of detection of interframe apertures are carried out. Principal components of development of technology of coding of a packet of the predicted frames on the basis of formation of a code are explained to positional numbers. Analytical expressions for an assessment of the maximum quantity of binary places on representation of a packet of the predicted frames are built. [ABSTRACT FROM AUTHOR]

Purpose. The improvement of the calculation technique, which allow us to calculate the tumbling mill open gearing taking into account the load features and partial teeth contact. Methodology. The generalization of the experimental data of nonuniformity of load distribution by gear width to straight cylindrical gearing of tumbling mill. Findings. The factors, which have effect to load distribution by contact line, the actual behavior of the tumbling mill open gearing loading, the features of stress calculation taking into account partial teeth contact have been established. It is shown that assembling conditions, resilience and face runout have main influence to irregularity of load distribution by contact line. It is established that the misalignment of axes caused by the seating descent is possible during the mill operation. It is determined experimentally that the load distribution by straight ring gear width is linear. The form of irregularity of load distribution various against the teeth pair connection. The teeth pair which is most loaded and has sufficient irregularity of load distribution, is existing. At the same time in most cases of contact the teeth contact not takes place at all width of ring gear. It is shown, that the rigidity of tumbling mill open gearing is lower than the rigidity which is presented in traditional techniques. Originality. The low of load distribution by contact line of tumbling mill open gear has been established. The calculation technique of factor taking into account the nonuniformity of load distribution during partial teeth contact has been proposed. Practical value. The basic data for the determination of factor taking into account the irregularity of load distribution by contact line has been determined. The features of the calculation of open gears taking into account the incomplete contact have been determined. [ABSTRACT FROM AUTHOR]

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This article highlights the longevity tests results of compact two-positioned electromagnetic pneumatic valves that are widely used in aviation and aerospace industry. Authors determined main degradation processes that take place in valve elements under the work loads and their influence on the efficiency of the electromagnetic valve and its functional parameters. It was revealed that change of the technical condition of valve components under the workloads is the result of two degradation processes: shock-fatigue destruction and impact-abrasive wear. Practical recommendations for increasing of work efficiency for this type of valves were created and introduced at JSCB «Kiev Central Design Bureau of Valves». Local standard «Methods of efficiency calculations for electromagnetic valves during design process» was created. [ABSTRACT FROM AUTHOR]

The method of the numerical investigations of stress-strain state of an element of roughness in the unit of friction in its elastic deformation under the influence of normal and tangential loading. The loss of stability under certain conditions of deformation is investigated. [ABSTRACT FROM AUTHOR]

The results of tribotesting materials triads «45XH2MΦA-LUKOIL-SUPER-AO20-1», «12X2H4- LUKOIL-SUPER-AO20-1, which allowed the established laws of changes in the factor of friction in the step of loading reveal the ambiguous nature of the formation of lubricating layer at the boundary friction action and their properties, as well as failure modes contacted surface, due to the influence of the chemical composition of the alloy structural steels in the adsorption - cohesive processes in the zone of friction. A key element in these lubricating layers forming patterns on surfaces are friction- cohesion adsorption processes occurring between the oil molecules and the active surface metal, in the presence of surfactants and without them. The simulation of stress modes of interaction elements of triboconjugation «pulley-block» at a constant frequency of rotation of the roller, ensuring their running-materials, including the lubricant. [ABSTRACT FROM AUTHOR]

Friction forces arising up in the polymer friction direct and reverse pairs and formed here specific loadings are shown in materials of the article. [ABSTRACT FROM AUTHOR]

Purpose. To compare the operability of exposed gearings of two-motor drives with those of one-motor drives and to analyze the ways of its reliable work. Methodology. The basis of calculation technique for the opened gearing deterioration is the mathematical model based on the result of synthesizing of experimental results and fundamental rules of the abrasion theory. It takes into account that velocity of teeth deterioration is depending on the parameters which characterize the influence of medium, physical and mechanical properties of constructional materials, geometrical and kinematical properties of gearings. Also it takes into account the deterioration velocity dependence on level of teeth deterioration. When the other parameters stay constant the main influence on opened gearing durability makes grinding velocity and load distribution along the contact line. Findings. The research shows that the ring gear and gear wheel teeth deterioration have the progressive nature if the hardness of gear wheel teeth is HB 300 and the hardness of the ring gear teeth is HB2 200. And for twomotor drives the longevity of ring gear makes 5-6 years. The radical method of solving the problem of opened gearings durability is rising of the teeth surface hardness. But this method results in teeth grinding speed lowering, and consequent nonuniformity of load distribution along contact line and, finally, lowering of teeth strength. Therefore, to ensure safe performance of the opened gearing the rising of production and assembling accuracy and upsizing of tooth module is required. Originality. The regularities of opened gearing deterioration have been determined. It is shown, that one of the general problems of the tumbling mill two-motor drive creation is the maintenance of opened gearing reliability. Practical value. The ways of improvement of the reliability of the tumbling mill two-motor drive opened gearing have been shown. [ABSTRACT FROM AUTHOR]