The effect of pressure on the compressibility of aluminum alloys

To obtain reliable data on the properties of liquid metal and create automated control systems, the technological process of molding with crystallization under pressure is studied. A mathematical model of the input and output process parameters is developed. It is established that the compressibility of the melt can represent the main controlled parameter influencing on the physical-mechanical properties of the final products. The obtained castings using this technology are not inferior in their physical and mechanical properties to those produced by forging or stamping.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jagat Kumar Shrestha ◽  
Sujit Bhandari

Masonry walls with distinct layers, known as multi-leaf masonry walls, are prevalent in many regions of the world including ancient architecture in Europe and new construction in the Himalayan region of South Asia. This paper presents a model for determining the capacity of multi-leaf stone masonry wall from its physical and mechanical parameters. For the study, a “Standard Wall” with typical properties of a multi-leaf stone masonry wall is defined and the capacity of the stone masonry wall is studied varying different physical and mechanical parameters of the wall to explore an analytical model that can represent the capacity of multi-leaf stone masonry. 300 models of multi-leaf stone masonry panels are analysed in ANSYS, and the capacity and displacement parameters are extracted by bilinearization of the pushover curve. As a result, a mathematical model between the capacity of a multi-leaf stone masonry wall and physical and mechanical properties is established.


2021 ◽  
Vol 244 ◽  
pp. 04007
Author(s):  
Nikolay Plotnikov ◽  
Olga Burova

The purpose of the conducted experimental studies is to examine the effect of various influences on the object of study. These effects are called factors. Some of them vary while examining of the object and then they are called variable factors. Each factor takes one or more values in the experiment and then they are called factor levels. The set of values of this factor is called range of factor values – the smallest interval, where are all the values accepted by this factor in the experiment. According to GOST 19222-84, the dependence of the physical-mechanical characteristics of sawdust slag concrete (grade M10) on the specific gravity (share) of wet sawdust of coniferous species and ash-slag mixture in the composition was studied. Regression analysis was used to build a mathematical model of the process with quantitative factors, to verify its adequacy, and to assess the impact of each variable factor on the process. To obtain regression dependencies, a composite second-order B-plan was implemented.


2018 ◽  
Vol 9 (3) ◽  
pp. 485
Author(s):  
Anna V. CHELOVECHKOVA ◽  
Irina V. KOMISSAROVA ◽  
Dmitry I. EREMIN

A technique is proposed for forecasting water saturation of fill and undisturbed grounds used in construction when making a foundation. Dependencies are established between the content of individual granulometric fractions of grounds and their physico-mechanical properties. Reliable regression equations are obtained, which formed the basis of a mathematical model for predicting the water saturation of grounds. A software product has been developed, the work of which was tested using the example of the basic hydro-physical characteristics of the grounds differing in their properties (black earth and salt earth). The results obtained reliably prove the possibility of using the model and software product in a wide range of granulometric composition values and physical and mechanical properties of grounds.


2020 ◽  
Vol 210 ◽  
pp. 08014
Author(s):  
Alexey Dyachenko ◽  
Tatiana Savostina

The present article is oriented on development of engineering and design parameters of a threshing separator designed as hyperboloid of revolution of one nappe for grain crop harvesting. Dependence of optimized cutting profiles on physical and mechanical properties of grain mass and parameters of a threshing separator is defined to ensure uniform supply of grain mass to threshing. The mathematical model of the profile defining process is developed to ensure uniform supply of grain mass to threshing.


Author(s):  
Anatolii Zhuchenko ◽  
Ruslan Osipa ◽  
Liudmyla Osipa ◽  
Dmytro Kovaliuk

At the present stage of technical progress, all industries face an extremely complex problem of creating reliable barriers that prevent the penetration of industrial emissions into the environment. Currently, the issues of stabilizing the quality of wastewater treatment have become especially important in connection with the task of developing wastewater-free industrial complexes. Among the complex scientific and technical problems associated with this task, the problem of stable and reliable maintenance of water quality parameters at the outlet of technological systems is crucial, as leakage of pollutants immediately affects the state of basic production, disrupting its technology and infecting ecosystems. The focus of industry on a sharp reduction in emissions and on the creation of industrial cycles with circulating water supply requires intensive efforts to improve the wastewater treatment technology, the introduction of high-performance processes and devices, as well as the synthesis of control systems for typical wastewater treatment processes. For the performance of automated control systems for typical cleaning processes, it is necessary to develop a software package on the basis of appropriate mathematical models of typical processes. To obtain them, methods of mathematical and simulation modeling and variance analysis were used. In order to assess the quality of modeling, the presented mathematical model describing the statics of the neutralization process for ferrous sulfate water was tested for compliance. To do this, two experiments were performed (the first at an initial concentration of sulfuric acid of 800 [mg/l] and ferrous sulfate of 4000 [mg/l] and the second at an initial concentration of sulfuric acid of 800 [mg/l] and ferrous sulfate of 2000 [mg/l]). First of all, a precondition for the reproducibility of experimental results was verified using the Cochrane test. The mathematical model was verified for adequacy on the basis of Fisher's criterion for the significance level q = 0.05 with degrees of freedom j1 = 16 and j2 = 17. For the first experiment, Grozr = 0.50557 and Gmab = 0.73; i.e., Grozr < Gmab and dispersions are homogeneous. Frozr = 1.0225 and Fmab = 2.4 and thus Frozr < Fmab, and there is no reason to say that the model is inadequate. For the second experiment, Grozr = 0.50308 and Gmab = 0.73; i.e., Grozr < Gmab and dispersions are also homogeneous. Frozr = 1.0005 and Fmab = 2.4 and thus Frozr < Fmab, which also indicates that the model is adequate. The issue related to the performance of technological systems for wastewater treatment in non-stationary modes is directly dictated by the specific operating conditions of treatment facilities, which are expressed by the instability of parameters at their inlet. The inability to apply the necessary technological action to the flow in time is a serious obstacle to the implementation of the cleaning depth, which is guaranteed by the physicochemical basis of the methods incorporated in technological systems and requiring cleaning standards. The operator cannot handle this complex task manually. On the basis of the proposed mathematical model, a structural-parametric diagram of the automated process control system has been developed, which makes it possible to proceed to the elaboration of algorithms and software for the control system necessary for automated control of the wastewater treatment process.


2002 ◽  
Vol 16 (04) ◽  
pp. 135-141
Author(s):  
MARIANA POP ◽  
TRAIAN CANTA ◽  
AUREL POP

The aim of this paper is to present a mathematical model for the steady state of the dieless drawing process. With this model, it is possible to study the influence of various process parameters, such as temperature, strain, strain rate and stress. The paper also presents some elements of the process control for producing variable cross-sections (cone-contour and sinus-contour).


Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.


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