ANALYTICAL SUBSTANTIATION OF THE RATIONAL MODE OF VIBRATION IMPACT ON THE HONEYCOMB

Проблема и цель. Заключается в том, чтобы теоретически обосновать режим виброочистки воскового сырья, при котором происходит отделение частиц воска от перговых гранул. Методология. В результате вибрационного воздействия на соты с пергой действует вынуждающая сила, которая должна быть больше силы трения между перговой гранулой и восковой основой ячейки сота, для того чтобы гранулы перги отделились. Увеличить силу, действующую на гранулу, можно увеличением либо амплитуды, либо частоты колебаний. Управление частотой является более рациональным по сравнению с управлением амплитудой. Для расчета частоты и амплитуды вынуждающей силы используются следующие данные: 2h – толщина рамки с сотами, h = 0,01м; a – длина рамки с сотами, a = 0,3м; b – ширина рамки с сотами, b = 0,4м; ρ – плотность, ρ = 326 кг/м³; N – натяжение; g – ускорение свободного падения, g = 9,81 м/c²; E – модуль упругости, E = 206000 МПа; G – модуль сдвига, G = 74000 Мпа; ν – коэффициент Пуассона, ν = 0,3; υ – коэффициент вязкости. Моделирование исследуемого процесса выполняется в среде Mathcad встроенными средствами статистической обработки. При этом осуществляется математическое моделирование в определенных рамках технологического процесса. Результаты. При воздействии на рамки с сотами, в которых есть перга, гармоническими колебаниями, возникает резонанс на малых частотах, что помогает ускорять процесс очистки. Заключение. Для наиболее качественной очистки воскового сырья от примесей необходимо воздействие вибрации с частотой в диапозоне от 14 до 16 Гц. При этом возникает резонанс, который уменьшает затраты энергии на данный процесс. Problem and purpose. The aim of the study is to theoretical justify the mode of vibration cleaning of wax feedstock, in which wax particles are separated from beads. Methodology. As a result of the vibration action, a force force is exerted on the feather honeycombs, which must be greater than the frictional force, in order for the feather pellets to separate from the wax cells of the honeycombs. To calculate the frequency and amplitude of the force, the following data 2h are used - the thickness of the frame with cells, h = 0.01m; a is the length of the frame with cells, a = 0.3m; b is the width of the frame with cells, b = 0.4m; ρ - density, ρ = 326 kg/m3 ; N - tension; g - acceleration of free fall, g = 9.81 m/c2 ; E - modulus of elasticity, E = 206000 MPa; G - shear modulus, G = 74000 MPa; v is Poisson's coefficient, v = 0.3; υ - viscosity coefficient. Results. When acting on frames with cells in which there is a feather, harmonic oscillations, resonance at low frequencies occurs, which helps to accelerate the cleaning process. Conclusion. For the highest quality purification of wax raw materials from impurities, vibration is necessary with a frequency in the diapozone from 14 to 16. At the same time, a resonance occurs that reduces the energy consumption for this process.

SIMULATION AND BIFURCATION ANALYSIS OF GEOTECHNICAL SYSTEM STABILITY UNDER VIBRATION

The automation of control processes for the stability of geotechnical systems is a great challenge involving the development of methods for multivariate analyzing and forecasting the stability with the subject to the nonlinearity of material stiffness parameters. The aim of the study is to improve the efficiency of automated control systems for geotechnical stability by developing an approach to detect negative changes in bifurcation diagrams of vibration displacement parameters of object structures. The authors present a mathematical model of the dynamic behavior of structural elements of an object as an elementary unit of a geotechnical system that describes a response to an external vibration action. An algorithm of bifurcation analysis is presented, which allows authors to determine the initial transition stage of the object structure to an unstable state by the acceleration values of forced oscillations exceeding the model parameters. A bifurcation diagram of stability changes in the structure of object at the displacement resulting from the load increase under vibration action has been constructed. This diagram, which type of codimension-one bifurcations is merging, enabled to determine the critical load values resulting in an unstable state transition of a system due to the influence of a combination of vibration factors. The efficiency evaluation of the proposed approach was carried out by the comparison with the results of construction stability calculations obtained by the use of the dynamic coefficient. The difference between the values of the maximum object displacement without loss of the stability under vibration action, obtained by the standard calculation method and using the developed model, is 32.5%, and it is significant in the theory of structure stability. When exogenous vibration noise is used as a source of a sounding signal, the application of the developed approach in automated control systems for geotechnical stability enable to change the permissible stability thresholds of objects being exploited depending on the level and combination of influencing factors.

Innovative Crushing and Grinding equipment of Vibration Action

Based on the vibration method of disintegration, new crushing and grinding machines have been created, in which the intra-layer dynamic destruction of the material is realized by a combined vibration-pulse compression with a shift. The design and technological features of vibration crushers are considered, as well as the experience of their industrial use in the processing of various types of raw materials, including industrial waste. It is shown that vibration disintegration provides efficient processing of production wastes and higher technical and economic indicators in comparison with traditional technologies. The sufficiently long operating experience of the created vibration machines proves a real reduction in energy consumption by up to 30%, especially for highly hard materials.

Stability of the Railway Subgrade under Condition of Its Elements Damage and Severe Environment

Investigation of damages of the subgrade slope in combination with its overwetting and rolling stock loading, which significantly affects safety traffic of the railway transport, has been carried out. The complex method of slope stability estimation of the subgrade is developed, which includes calculation of loads and vibration action of rolling stock on the main site of the subgrade, as well as the dynamic model of vibrations propagation in the body of the subgrade embankment and the model of plastic deformations accumulation. Dynamic and nonlinear plastic models are based on a finite-element model of the cross section of the subgrade. The plastic model takes into account the characteristics of soil strength of the subgrade, depending on the area of the vibration load impact. The developed method allows to carry out the estimation of external and internal factors impact on occurrence of subgrade destruction, which is of practical value for safety state estimation of the railway transport.

Whole-Body Vibration Exposures Among Solid Waste Collecting Truck Operators

A number of studies have shown an association between whole-body vibration (WBV) exposure and the onset and development of low back pain among professional vehicle operators. This study measured WBV exposures from 12 drivers who operated four different types of solid waste collecting trucks during part of their regular work shift. The daily average weighted A(8), vibration dose value VDV(8), and vector sum A(8) and VDV(8) exposures were analyzed and compared across the solid waste collecting trucks. Study result showed that the majority of A(8) and all of the VDV(8) predominant axis exposures were above International Organization for Standardization (ISO) daily vibration action limit (A(8) = 0.5 m/s2, VDV(8) = 9.1 m/s1.75). Based on the predominant axis and vector sum exposures, most of the trucks reached the daily vibration action limits before 8-hours. When compared to the predominant axis A(8) exposures, the predominant axis VDV(8) exposures reduced the acceptable solid waste collecting truck operating times on average by over 4 hours. Our study results demonstrated that these solid waste collecting truck operators were exposed to high levels of both continuous and impulsive WBV exposures, with the impulsive WBV exposures indicating that they may pose a greater risk to the driver’s health.