scholarly journals Modeling of physical wear assessment of zinc coating of space steel frame road structures for road safety information systems

2021 ◽  
pp. 25-31
Author(s):  
Serhiy Bilyk ◽  
Artem Bilyk ◽  
Eugen Tsyupyn ◽  
Oleksandr Glitin
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Safety Information ◽  
Zinc Coating ◽  
Atmospheric Precipitation ◽  
Corrosive Wear ◽  
Full Scale ◽  
Operating Conditions ◽  
Structural Elements ◽  
Steel Trusses

The article developed an improved physical and mathematical model of the corrosive wear of zinc coating of steel structures in a city. The research is based on full-scale experimental data for determining the wear of a zinc coating of full-scale metal spatial structures of frame road structures for informational safety systems on roads after 10 years of operation in the conditions of Kyiv. The frame structure consists of metal columns and a steel crossbar frame. The crossbar frame is a spatial block of two steel trusses. The block of trusses is assembled from unified spatial sections united by vertical and horizontal ties, and which are connected by flange nodes of a special design. All structural elements are made of rolled tubes. Based on the research results, an approach to assessing the physical wear of the zinc coating of the spatial structural system is proposed. According to the peculiarities of the arrangement of elements in frame structures, and, accordingly, to different conditions and operations, an approach is proposed to assess the corrosive wear of a zinc coating for various groups of elements: columns, spatial block of two steel trusses, flange nodes. The physical and mathematical model is based on the working hypothesis of uneven wear of the zinc coating over time. It was found that for each group of structural elements, the conditions of the gaseous environment, the effects of atmospheric precipitation, wind speed, temperature changes individually affect the reduction of the zinc coating. The obtained experimental data were used to determine the parameter of the rate of decrease in the zinc coating of the physical and mathematical model. The results of the research and the development of the methodology helped to establish the operating conditions of the zinc coating according to the criterion of the rate of wear of the zinc coating, to classify the category of aggressiveness of the environment for each group of structural elements. Also, studies allow predicting the service life by reducing the thickness of the zinc coating, as well as the wear of the zinc coating in time in the subsequent period of operation. The methodology is universal and can be extended to other types of galvanized metal structures.

scholarly journals Modeling the stress-strain state of a circular plate subject to general corrosion according to various models

2021 ◽  
Vol 263 ◽  
pp. 03009
Author(s):  
Ilya Ovchinnikov ◽  
Vladimir Avzovin
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Circular Plate ◽  
Strain State ◽  
Corrosive Wear ◽  
Operating Conditions ◽  
General Corrosion ◽  
Stress Strain ◽  
Stress Strain State ◽  
Kinetics Of

Quite a lot of works have been devoted to the problem of modeling the behavior of thin-walled structures exposed to an aggressive environment leading to corrosive wear of their surface. Researchers have proposed a fairly large set of models of corrosive wear, taking into account the influence of various factors on the kinetics of corrosion (time, material, temperature, the nature of the corrosive environment, the stress-strain state of the structure). Moreover, different authors often propose different models for the same conditions. In the article under consideration, a rather unique comparative study of three corrosion models proposed by different authors (Dolinsky V.M., Gutman E.M., Ovchinnikov I.G.) was carried out to simulate the behavior of the same circular plate subjected to the combined action of load and corrosion wear and tear. Moreover, the identification of the models, that is, the determination of the coefficients included in them, was carried out using the same experimental data. These models were then used to simulate the behavior of plates subject to corrosive wear under various loads. The results of numerical simulation were compared with experimental data obtained during testing of corrosive plates. Interestingly, in the models used, the effect of the stress state on the kinetics of corrosion was taken into account using different invariants of the stress state: the stress intensity in V.M. Dolinsky, medium voltage in the model of E.M. Gutman, and the specific energy in the model of I.G. Ovchinnikov. The analysis showed that the difference from the experiment when using the three models considered does not exceed 9.3%. The discrepancy between the results obtained using different models is also within the acceptable range, which suggests that all three models can be used to predict the behavior of plates under corrosive wear conditions. However, it is of interest to conduct research on the predictive capabilities of models on large forecast arms that go beyond the scope of experimental studies. At the same time, carrying out numerical experiments to simulate the behavior of complex structures in a stressed state and subject to corrosive wear, using several models that allow a good description of the experimental data and the most complete consideration of the operating conditions, makes it possible to obtain a more complete and versatile picture of what is happening in design processes, in comparison with the calculations performed according to one model, even if it describes the experimental data well.

Simulating the effect of blanket characteristics on the floc blanket clarification process

1997 ◽  
Vol 36 (4) ◽  
pp. 77-84 ◽  
Author(s):  
Richard Head ◽  
Jem Hart ◽  
Nigel Graham
Keyword(s):  
Mathematical Model ◽  
Water Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Treated Water ◽  
Treatment Conditions ◽  
Model Predictions

Previous attempts at simulating the floc blanket clarification process have failed to predict adequately the performance of ‘real’ tanks on water treatment works over a range of treatment conditions. In this paper, a mathematical model of the floc blanket clarification process is presented. This model has been used to simulate the performance of a flat-bottomed clarifier operating on a full-scale water treatment works. The model predictions have been compared with data obtained from the treatment works, and the model has been shown to perform well. The model has then been used to simulate the effects of changes in the operating conditions of the clarifier on the concentration of the blanket in the clarifier and the quality of the treated water. The importance and potential uses of a model of the process at a treatment works are discussed.

Experimental study and first thermodynamic law analysis of a solar water heater system

2015 ◽  
Vol 40 (3) ◽  
Author(s):  
Vahid Madadi ◽  
Hamid Beheshti ◽  
Touraj Tavakoli ◽  
Amir Rahimi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Study ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Solar Water Heater ◽  
System Efficiency ◽  
System Behavior ◽  
Water Heater ◽  
Solar Water

AbstractThe performance of a pilot scale flat plate solar water heater system is investigated theoretically and experimentally. The effect of the operating conditions and characteristic factors of the collector on the system efficiency is studied. A conceptual mathematical model is developed in order to analyze the system behavior in different operating conditions by considering the physical and constructive aspects of the system. The accuracy of the model result is estimated by comparing the model results with the existing experimental data. The highest obtained system thermal efficiency is 45%, and the optimum local values for surface azimuth and tilt angles are obtained at 180 degrees from north and 33 degrees, respectively, for the constructed solar water heater in Isfahan, Iran, with the local latitude of

Modeling the operability of pumping equipment in arctic operating conditions

2020 ◽  
pp. 108-111
Keyword(s):  
Low Temperatures ◽  
Full Scale ◽  
Operating Conditions ◽  
Gear Pump ◽  
Structural Elements ◽  
Hydraulic Machine ◽  
Pumping Equipment

An example of modeling the gear pump operability under arctic operating conditions is considered. The failures causes analysis of the normal design is carried out. The results of modeling the structural elements of a hydraulic machine under conditions of low temperatures influence are considered. Verification of performance according to the results of full-scale climatic tests is carried out.

The substantiation of the formalized estimation of effectiveness of technological and production systems

2018 ◽  
Vol 15 (1) ◽  
pp. 169-181
Author(s):  
M. I. Sidorov ◽  
М. Е. Stavrovsky ◽  
V. V. Irogov ◽  
E. S. Yurtsev
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Production Systems ◽  
Van Der Pol

Using the example of van der Pol developed a mathematical model of frictional self-oscillations in topochemically kinetics. Marked qualitative correspondence of the results of calculation performed using the experimental data of researchers.

A Critical Look into the Deviation of Full Scale Performance from Design Expectations

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1389-1402 ◽  
Author(s):  
R. Zaloum
Keyword(s):  
Expert Systems ◽  
Waste Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Organic Load ◽  
Computer Assisted ◽  
Uniform Load ◽  
Effluent Quality ◽  
Simulation Techniques ◽  
Steady Level

Deviations from design expectations appear to stem from views which assume that a unique response should result from a given set of operating conditions. The results of this study showed that two systems operating at equal organic loads or F/M ratios and at the same SRT do not necessarily give equal responses. This deviation was linked to the manner in which the HRT and influent COD are manipulated to obtain a constant or uniform load, and to subtle interactions between influent COD, HRT and SRT on the biomass and effluent responses. Increases of up to 200% in influent COD from one steady level to the next did not significantly influence the effluent VSS concentration while an effect on filtered COD was observed for increases as low as 20%. Effluent TKN and filtered COD correlated strongly with the operating MLVSS while phosphorus residual depended on the operating SRT and the organic load removed. These results point to the inadequacy of traditional models to predict effluent quality and point to the need to consider these effects when developing simulation techniques or computer assisted expert systems for the control of waste treatment plants.

Validation of mathematical model of electrothermal calculation of DC catenary on the basis of scale model

2018 ◽  
Vol 77 (4) ◽  
pp. 222-229 ◽  
Author(s):  
A. V. Paranin ◽  
A. B. Batrashov
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Scale Model ◽  
Contact Network ◽  
Scaled Model ◽  
Cross Sectional ◽  
Current Collection ◽  
Topological Features ◽  
Study Results ◽  
Real Physical Process

The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

scholarly journals Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1592
Author(s):  
Dominik Gryboś ◽  
Jacek S. Leszczyński ◽  
Dorota Czopek ◽  
Jerzy Wiciak
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Noise Reduction ◽  
Sound Pressure ◽  
Acoustic Pressure ◽  
Pressure Level ◽  
Computational Results ◽  
Noise Measurements ◽  
Exhaust Noise ◽  
Collecting System

In this paper, we demonstrate how to reduce the noise level of expanded air from pneumatic tools. Instead of a muffler, we propose the expanded collecting system, where the air expands through the pneumatic tube and expansion collector. We have elaborated a mathematical model which illustrates the dynamics of the air flow, as well as the acoustic pressure at the end of the tube. The computational results were compared with experimental data to check the air dynamics and sound pressure. Moreover, the study presents the methodology of noise measurement generated in a pneumatic screwdriver in a quiet back room and on a window-fitting stand in a production hall. In addition, we have performed noise measurements for the pneumatic screwdriver and the pneumatic screwdriver on an industrial scale. These measurements prove the noise reduction of the pneumatic tools when the expanded collecting system is used. When the expanded collecting system was applied to the screwdriver, the measured Sound Pressure Level (SPL) decreased from 87 to 80 dB(A).

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