The article presents the method of appointment of the composition of the molding mixture, which is based on the calculation and experimental approach. The results of the research served as the basis for the practical implementation of the proposed technological method of increasing the durability of small-sized products made of fine concrete. The article was published in the framework of the program of the International Forum "Victorious may 1945»
Keywords: workability of concrete mix, water-cement ratio, grain composition, raw materials, concrete, acidic medium, sodium sulfate, durability, small products, classification of defects, vibration mixing, technological methods
The quantitative methods of risk assessment of technological processes of manufacture and the analysis of level of deficiency of products in the conditions of nondeterministic stochastic parameters are considered. The properties defining reliability of process are its controllability, stability and reproducibility. The main methodical device by assessment and the analysis of these properties are provisions of standards on statistical methods of quality control. In the analysis and assessment of risk it is necessary to consider that borders of a tolerance zone of parameters of products and control limits of reliability of technological processes of its production are always considered as acceptable (admissible) risk levels. Overcoming these levels is considered a negative consequence in the form of increase in level of deficiency of products and decrease in accuracy of technological processes of its production. Technical solutions are always bound to risk as it is never impossible to be sure of the end estimated result in advance. To check whether this risk was justified, it is possible always only after realization of technical solution and approach of an undesirable event. Therefore technical activity in principle can't be completely free from any risk, and it is always necessary to go on necessary and justified risk consciously.
Keywords: technical system, technological process, risk, indeterminacy, management of reliability, negative event, damage, nondeterministic stochastic parameter
The article presents a description of the device for determining the physicomechanical characteristics of bulk materials - coefficients of external and internal friction. In DSTU, a device for determining the friction characteristics of bulk materials was designed and manufactured. A method for determining the coefficients of static and dynamic friction is presented. The proposed device allows to obtain more accurate information about the frictional characteristics of one or different bulk materials in static and dynamic conditions.
Keywords: Friction, dynamic coefficient of friction, static coefficient of friction, bulk material
The problem of calculating rods for vector perturbations consisting of five components is solved: 1. kinematic transverse vibrations of the left end; 2. kinematic transverse vibrations of the right end; 3. dynamic bending moment at the left end; 4. dynamic bending moment at the right end; 5 dynamic uniformly distributed lateral load along the length of the rod. The transfer functions from each disturbance are obtained separately. Using these functions, we obtained the elements of the spectral matrix for stationary random processes, taking into account their correlation. The most common types of processes are considered: exponentially correlated random process; process with latent periodicity (with characteristic frequency); truncated white noise. The formula for obtaining the dispersion of displacement of sections is shown.
Keywords: rod, harmonic oscillations, natural frequency, kinematic disturbances, dynamic disturbances, transfer function, correlation matrix, random process, delta-correlated random process, latent periodicity, truncated white noise
The following work looked into sensitive analysis. Sensitive analysis is used to gather some data of analysed problem and further to reduce the time required to run a simulation. The work explains importance of the tool in field of mechanics engineering. The work briefly outline applications of the tool in industries. Also I-beam analysis was done to better understand influence of sensitive analysis. The results illustrated that by reducing nodes in the geometry of the I-beam the output values stay the same, but too much reduction will lead to incorrect results. The comparison of the two methods also took a place in this work, to see the correlations and discrepancy of the problem.
Keywords: sensitive analysis, time reduction, finite element, I-beam, simulation
This work investigates squeal propensity problem arising during normal braking. Narrative of this work is suggesting complex eigenvalues method to found out tendency of squeal propensity. The work also provides a brief introduction of complex eigenvalues method and literature review of the problem, which shows study done in this field by other investigators. Frequencies and instability measurements were calculated. Afterward standard deviations were plot to found out whether squeal will be reduced or amplified, within chosen parameters. The results illustrated that by increasing the coefficient of friction the instability measurement will increase and reduce when hydraulic pressure increased.
Keywords: complex eigenvalues, squeal propensity, standard deviation, brake system, squeal reduction, instability measurements
This article presents the results of an experimental study of the deep cooling of natural gas combustion products in a condensation heat exchanger of a waste heat exchanger in a boiler house No. 12 at the Federal State Budgetary Educational Institution of Higher Education "National Research Ogarev Mordovia State University". The heat scheme of the boiler house with the flue gas heat exchanger provides the maximum continuous cooling mode. The study identified the factors that have the greatest impact on the efficiency of the heat exchanger-utilizer.With short-term operation of the boiler in the spring and autumn periods, the efficiency is more than 3%.
Keywords: burner, combustion mode optimization, heat utilizer, boiler room thermal circuit, boiler unit, flue gases, condensation, heat exchanger, cogeneration mode, cooled gases
A program has been developed that allows to evaluate the adhesion of paint coatings by means of analyzing images of the surface of coatings with delamination’s from the substrate to be protected. The program is written in Kotlin using JavaFX platform and is focused on tests carried out by the method of lattice cuts within the conditions of paint and varnish production. Through the work the evaluation of the area of the coating detachment from the surface to be protected is being held and the obtained result is scored by points according to the method of lattice cuts. The use of the program does not require a large computing power of the computer and reduces the time for obtaining the calculating results for one sample from 20 minutes to 3 seconds.
Keywords: adhesion, lacquer coatings, notch method, Kotlin language, JavaFX
This article discusses the possibility of improving the environmental situation by changing the percentage ratio of metal and fiberglass fittings produced in the direction of increasing the latter. A comparative analysis of the calculation of the slab basement of 300-mm thickness was carried out, in the construction of which reinforcement made of steel (class A-500C) - and fiberglass were used. The results of the study led to the conclusion that, due to the recycling of plastic waste to produce this innovative building material, there is great savings for the manufacturer, and to this is added an improvement in the environmental situation in general, as the amount of industrial waste on the globe decreases without using environmentally friendly methods. destruction.
Keywords: Operation and reconstruction, design, construction safety, operation, fiberglass reinforcement, construction
The article deals with the main problems of obtaining experimental data on drying liquid dispersed products. The main difficulties of using a moisture meter to obtain kinetic curves of drying difficult-to-dry liquid materials are given. On the example of lignosulfonate drying curves of samples of liquid product in different conditions are obtained. Presented that the application of the proposed method of the experiment on the moisture meter does not lead to early completion of the operation of the analysis of the drying process.
Keywords: kinetics, moisture meter, drying, moisture, solvent, evaporation, lignosulfonates
This scientific study presents an analysis of organizational conflicts, as well as problematic aspects of activity in contemporary realities. The effect of organizational conflict on the effectiveness of an individual is shown. The urgency of researching the problem of the activities of the organization’s employees in the context of organizational conflicts, as well as ways to solve them, is given The analysis of the cognitive model. As factors used to reduce tensions in a team, it was proposed to introduce factors for raising qualifications and organizational culture. These factors will influence the target factor - performance. In the course of simulation modeling, it was found that by carrying out activities to improve the skills of employees, measures to increase the level of organizational culture of employees, the organization seeks to reduce tension in the team and, as a result, there is less staff turnover.
Keywords: simulation modeling, cognitive modeling, functional structural analysis, visual analytics, conflict, organization, model, social tension
This article describes problems of ensuring the reliability of gas pipelines, one of which is connected with the construction of the North Seas on the shelf in the zone of permafrost soils, the other with the construction of long-distance gas pipelines in difficult hydrological conditions. Were analyzed the existing technical solutions in the light of the above construction conditions. Were revealed the advantages and disadvantages of the considered technologies of construction and transportation of gas are. The research identifies the main factors affecting the reliability and efficiency of design solutions for the construction of gas pipelines in areas with difficult hydrometeorological conditions.
Keywords: reliability of gas pipelines, analysis of technical solutions, complex hydrometeorological conditions, gas transportation
The following work is concentrated on the analysis of dynamic pressure distribution of a brake pad by using ANSYS software. A non-linear contact analysis of brake disc has been performed using Finite Element Method. The finite element model of disc and pads have been developed, and followed by an inclusive simulation of the contact analysis of disc brake system using ANSYS software. A detailed finite element model of a disc brake assembly was developed. Contact analysis was done to determine the pressure distribution, interfacial contact area and normal contact forces under both frictionless (μ=0) and frictional braking conditions. The influence of varying friction coefficients and the brake hydraulic pressure on squeal occurrence is examined. The results illustrated that the contact pressure distribution and the magnitude of normal contact pressures are far greater towards the leading edge of the pads comparing to the trailing edge.
Keywords: метод конечных элементов, распределение давления, контактное давление, шум, тормозная система , нелинейный контактный анализ
The article is devoted to the conditions and tasks of the methodology of adaptation and preparation of information models of buildings and structures for subsequent implementation and effective application in the system of technical operation of the building. The following issues are addressed: analysis of the use of BIM-model at the operational stage; analysis of the difficulties encountered when using unprepared BIM-model in operation; synthesis of existing and development of alternative recommendations for filling the information model with data at each stage of design and construction for subsequent use in the operation service; the study of tools that help in the preparation of BIM-model; development of algorithms that optimize the preparation of an information model for the operation of an object.
Keywords: BIM-technologies, information modeling, construction, 3D-model, virtual copy, construction
This article will analyze the effect of Gc on the propagation of cracks in glasses with different material properties. The analysis demonstrated that with decreasing Gc, the crack length will increase and, with a larger applied force, the effect of Gc on the crack propagation in the structure decreases.
Keywords: fracture mechanics, fats fracture, Gc, crack propagation, Code_Aster, Solome Meca