Software architecture for determining the measurement error of the part dimensions by the optical method

Рассмотрена актуальность бесконтактных методов измерений размеров и описано программное обеспечение, позволяющее определять оптические искажения результатов измерений

The solution of wear-contact problems by means of electrical simulation

В статті розглянуто сутність електростатичної аналогії між рівняннями електростатики та теорії пружності. На основі цієї аналогії запропоновано спосіб вирішення задачі щодо контакту двох пружних тіл з врахуванням зносу за допомогою електричного моделювання з використанням квазістаціонарного електричного поля. Вирішена зносоконтактна задача щодо убчастого зачеплення. Отримано площадки контакту для різних варіантів контактування зубів з початковим точковим контактом. Досліджено вплив зносу контактуючих поверхонь на розподілення контактного тиску. Побудовані епюри контактного тиску по різним січенням площадок контакту.Purpose. A great number of works in the field of contact interaction mechanics including those with account of the wear of contact surfaces, and the desire to take into consideration the factors even at the stage of designing elements of higher kinematic pairs proves the topicality of the problem under consideration. However, solving such problems by means of analytical and numeric methods is connected with the necessity to overcome considerable difficulties, and in some cases it is impossible. That is why other methods of solving them, and, in particular, with help of electrical simulation are of both scientific and practical interest. Design/methodology/approach. The paper considers the essence of electrostatic analogy. It presents the way of solving 3D contact problems by means of electrical simulation based on the application of quasi-stationary electric field. It also presents the description of a special electrical simulation device made for solving the problems. The device enables to do experimental research and process obtained results automatically. It is shown that the accuracy of the results obtained in the experiments is enough for engineering applications. Findings. The paper also presents the problem about point contact of gear teeth with account of wear. It shows the influence of contact surfaces wear on the distribution of contact pressures. It presents contact areas for different points of gearing. The diagrams of contact pressures on their different sections are given. Originality/value. It is concluded that the solution of wear-contact problems enables to choose the best geometry of contact surfaces of elements of higher kinematic pairs on the designing stage and get a considerable economic effect.В статье рассмотрена сущность электростатической аналогии между уравнениями электростатики и теории упругости. На основе этой аналогии предложен способ решения задачи о контакте двух упругих тел с учетом износа с помощью электрического моделирования с использованием квазистационарного электрического поля. Решена износоконтактная задача применительно к зубчатому зацеплению. Получены площадки контакта для различных вариантов контактирования зубьев с первоначально точечным контактом. Исследовано влияние износа контактирующих поверхностей на распределение контактных давлений. Построены эпюры контактных давлений по различным сечениям площадок контакта

Anomalous attenuation of extraordinary waves in the ionosphere heating experiments

Multiple scattering of radio waves by artificial random irregularities HF-induced in the ionosphere F region may cause significant attenuation of both ordinary and extraordinary waves together with common anomalous absorption of ordinary waves due to their non-linear conversion into plasma waves. To demonstrate existence and strength of this effect, direct measurements of attenuation of both powerful pump wave and weak probing waves of extraordinary polarization have been carried out during an experimental campaign on September 6, 7 and 9, 1999 at the Sura heating facility. The attenuation magnitude of extraordinary waves reaches of 1-10 dB over a background attenuation caused by natural irregularities. It is interpreted in the paper on the base of the theory of multiple scattering from the artificial random irregularities with characteristic scale lengths of 0.1-1 km. Simple procedure for determining of irregularity spectrum parameters from the measured attenuation of extraordinary waves has been implemented and some conclusions about the artificial irregularity formation have been obtained.Comment: 17 pages, 9 figure

Generation of Artificial Ionospheric Irregularities in the Midlatitude Ionosphere Modified by High-Power High-Frequency X-Mode Radio Waves

© 2014, Springer Science+Business Media New York. We consider the properties of the artificial ionospheric irregularities excited in the ionospheric F2 region modified by high-power high-frequency X-mode radio waves. It is shown that small-scale (decameter) irregularities are not generated in the midlatitude ionosphere. The intensity of irregularities with the scales l⊥≈50 m to 3 km is severalfold weaker compared with the case where the irregularities are excited by high-power O-mode radio waves. The intensity of the larger-scale irregularities is even stronger attenuated. It is found that the generation of large-scale (l⊥ ≈5–10 km) artificial ionospheric irregularities is enhanced at the edge of the directivity pattern of a beam of high-power radio waves

Gyroharmonic features of the hf-induced ionospheric irregularities

Gyroharmonic features of the different-scale artificial plasma-density irregularities excited by HF modification of the ionospheric F2 region under conditions where the frequency of the O-mode pump wave is close to the fourth gyroharmonic frequency of electrons in the pump wave - plasma interaction region are considered. © 2012 Springer Science+Business Media New York

Some results of measuring the characteristics of electromagnetic and plasma disturbances stimulated in the outer ionosphere by high-power high-frequency radio emission from the “Sura” facility

International audienceWe present the results of measuring the characteristics of electromagnetic and plasma disturbances at altitudes of about 700 km, obtained by using the onboard equipment of the French microsatellite DEMETER during its passage through the magnetic tube resting upon the region of intense generation of artificial ionospheric turbulence created due to modification of the ionospheric F2 region by high-power radio emission from the “Sura” facility. It is shown that an artificial density duct emerging from the disturbed region and extending to the Earth’s magnetosphere can be formed

Density ducts formed by heating the Earth’s ionosphere with high-power HF radio waves

International audienceThe parameters of plasma disturbances at altitudes 660 and 840 km, measured by the instruments onboard the French DEMETER satellite and the US DMSP satellites passing through the magnetic flux tube footed at the region of intense modification of the F 2 ionospheric layer by the high-power HF radio waves of the Sura heating facility, are presented. The formation of artificial enhanced-density plasma ducts in the outer ionosphere is observed experimentally. Conditions facilitating the formation of such ducts are pointed out

Satellite measurements of plasma-density perturbations induced in the topside ionosphere by high-power HF radio waves from the “Sura” heating facility

International audienceWe report on the French DEMETER and American DMSP satellite measurements of largescale field-aligned plasma-density perturbations (ducts) induced in the topside ionosphere by the ionospheric F 2-layer pumping by means of high-power HF radio waves from the “Sura” heating facility. Characteristics of such plasma perturbations and conditions of their formation are determined