Forecasting Water Saturation of Fill Grounds in Urban Infrastructure Conditions by Mathematical Modeling Based on the Main Hydrophysical Characteristic

2018 ◽  
Vol 9 (3) ◽  
pp. 485
Author(s):  
Anna V. CHELOVECHKOVA ◽  
Irina V. KOMISSAROVA ◽  
Dmitry I. EREMIN
Keyword(s):  
Mathematical Modeling ◽  
Mechanical Properties ◽  
Mathematical Model ◽  
Granulometric Composition ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
Urban Infrastructure ◽  
Regression Equations ◽  
Wide Range ◽  
Software Product

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.

Control of properties and structure of steel vessels by cooling in various media at the outlet of rolling and pressing lines

2021 ◽  
pp. 34-38
Author(s):  
R. L. Shatalov ◽  
V. A. Medvedev
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Metal Structure ◽  
Machine Building ◽  
Regression Equations ◽  
Wide Range ◽  
Industrial Mineral ◽  
Cooling Media ◽  
Technological Limitations ◽  
Non Destructive

When controlling the mechanical properties and structure of vessels made of carbon structural steels manufactured by hot deformation on rolling and pressing lines (PPL) of machine-building enterprises of Russia, such cooling media as water, I20 industrial mineral oil, air are used. The applied cooling media are able to provide the workpieces with a given structure with a wide range of mechanical properties. However, the cooling media have a number of technological limitations and conditions of the use, non-compliance with which leads to reject. When cooled in oil, the probability of ignition is high; when cooled in water, hardening cracks may form, and air is not always able to provide the required rate and uniformity of heat transfer to the environment. The efficiency of control of physical and mechanical properties and structure of deformed vessels made of 50 steel by cooling in TERMAT polymer aqueous solutions in different concentrations on PPL of the plant of JSC NPO Pribor was studied. The effect of varying the concentration from 2 to 9% of TERMAT polymer on the formation of metal structure, as well as physical and mechanical properties of hot-deformed vessels was studied. The results of testing the strength and plastic characteristics of vessels by destructive and non-destructive control methods are presented. According to the results of physical and mechanical properties, regression equations were obtained with at least 95% reliability of R2, which establish the relationship between the controlled plastic and strength parameters of the vessel metal`s properties. The conducted researches allowed to compare the indicators of the main physical and mechanical properties of steel vessels at the PPL outlet and to propose methods of inhomogeneity control that reduce time and material costs by 5–10% during the tests.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

The effect of pressure on the compressibility of aluminum alloys

2020 ◽  
pp. 102-107
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Liquid Metal ◽  
Control Systems ◽  
Physical And Mechanical Properties ◽  
Reliable Data ◽  
Output Process ◽  
Automated Control ◽  
Input And Output ◽  
Crystallization Under Pressure

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.

Feeding Mathematical Modeling of Superalloy Vacuum-Electromagnetic Casting and its Application

2012 ◽  
Vol 629 ◽  
pp. 171-175
Author(s):  
Wen Zhong Jin ◽  
Su Fang Li ◽  
Wei Zhang
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
New Technology ◽  
Experimental Results ◽  
Electromagnetic Stirring ◽  
Shrinkage Cavity ◽  
Vacuum Casting ◽  
Electromagnetic Casting ◽  
Wide Range

The new technology of superalloy vacuum-electromagnetic casting was developed and the feeding mathematical model melt in vacuum-electromagnetic casting was established. The availability of mathematical model was approved by the experiments of the IN100 superalloy. The experimental results indicate that the feeding capacity of melt in vacuum casting can be greatly increased by imposing the 50Hz, 60A rotating electromagnetic stirring, which can decrease the central shrinkage cavity in superalloy ingots, so the quality of the superalloy ingots can be wide-range improved.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

scholarly journals Prosthodontic Applications of Polymethyl Methacrylate (PMMA): An Update

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2299 ◽  
Author(s):  
Muhammad Sohail Zafar
Keyword(s):  
Mechanical Properties ◽  
Polymethyl Methacrylate ◽  
Physical And Mechanical Properties ◽  
Mechanical Reinforcement ◽  
Occlusal Splints ◽  
Dental Prostheses ◽  
Wide Range ◽  
Dental Applications ◽  
Artificial Teeth ◽  
Orthodontic Retainers

A wide range of polymers are commonly used for various applications in prosthodontics. Polymethyl methacrylate (PMMA) is commonly used for prosthetic dental applications, including the fabrication of artificial teeth, denture bases, dentures, obturators, orthodontic retainers, temporary or provisional crowns, and for the repair of dental prostheses. Additional dental applications of PMMA include occlusal splints, printed or milled casts, dies for treatment planning, and the embedding of tooth specimens for research purposes. The unique properties of PMMA, such as its low density, aesthetics, cost-effectiveness, ease of manipulation, and tailorable physical and mechanical properties, make it a suitable and popular biomaterial for these dental applications. To further improve the properties (thermal properties, water sorption, solubility, impact strength, flexural strength) of PMMA, several chemical modifications and mechanical reinforcement techniques using various types of fibers, nanoparticles, and nanotubes have been reported recently. The present article comprehensively reviews various aspects and properties of PMMA biomaterials, mainly for prosthodontic applications. In addition, recent updates and modifications to enhance the physical and mechanical properties of PMMA are also discussed.

scholarly journals Specific solution of problem of water filtering in the rocks by the finite element method

2019 ◽  
Vol 109 ◽  
pp. 00093 ◽  
Author(s):  
Olena Slashchova ◽  
Ihor Slashchov ◽  
Iryna Sapunova
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
The Finite Element Method ◽  
Water Saturated ◽  
Element Method

The article is devoted to development of methods for geofiltration calculations with taking into account peculiarities of changes of the rock physical and mechanical properties at water saturation. Methods: mathematical modeling of geomechanical and filtration processes with the help of finite element method and laboratory and underground studies. A mathematical model was formulated for solving a problem of elasticity theory by the finite element method, which took into account peculiarities of water-saturated rocks. Pattern of stress-strain state changing in the fractured water-saturated rocks under the action of critical loads, which occurred around the preparatory roadways during their operation, were established. In order to solve the filtration problems, a bank of collected initial data on physical and mechanical properties of water-saturated rocks was processed with the help of variation coefficients, which were taken into account by the method, which assumed calculation of the model loading with critical parameters.

Features of mathematical modeling of wood-polymer composite sandy

10.12737/8462 ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 130-139
Author(s):  
Стародубцева ◽  
Tamara Starodubtseva ◽  
Аскомитный ◽  
Aleksey Askomitnyy
Keyword(s):  
Mathematical Modeling ◽  
Mechanical Properties ◽  
Mathematical Model ◽  
Initial Data ◽  
Algebraic Equations ◽  
Wood Polymer ◽  
Composite Interface ◽  
Input Form ◽  
The Mathematical Model ◽  
Wood Polymer Composite

This article describes a technique for modeling of wood polymer-sandy composite. Interface input form of initial data for modeling; differential equations underlying the mathematical model are presented. To solve the system of differential and algebraic equations computer program "Program to simulate the struc-ture and mechanical properties of wood polymer-sandy composite" is developed. The program, developed in the environment of Borland Delphi 7.0, programming language Object Pascal, is intended for modeling the mechanical behavior of wood polymer-sandy composite of given composition.

Modeling of Building Materials as Complex Systems

2017 ◽  
Vol 730 ◽  
pp. 412-417 ◽  
Author(s):  
Irina Garkina ◽  
Alexander Danilov ◽  
Yuri Skachkov
Keyword(s):  
Mathematical Modeling ◽  
Complex System ◽  
Differential Equation ◽  
Mechanical Properties ◽  
Time Series ◽  
Building Materials ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Epoxy Composites ◽  
Damping Properties

We considered the problems of mathematical modeling of composite materials in the example of the development of materials for the protection against ionizing radiation. Construction materials are provided as a complex system with the appropriate attributes. The structure and physico-mechanical properties of the material were determined by the results of the modeling of kinetic processes. Process of forming properties is described by the differential equation in deviations from the equilibrium state (as for dispersion system). It is taken into account the elastic and damping properties of the material. To predict the behavior of the building material and the formation of his private mathematical models are used a representation of the processes as of time series. It is given the algorithm for studies (with considering prehistory) of formation of the basic physical and mechanical properties of epoxy composites for radiation protection. We present an example of the identification of building materials with special properties. Approaches used effectively in the development of materials with special properties.

Hall-Petch and Multiple Linear Regression Equations for the Prediction of Mechanical Properties in Gamma-Based Titanium Aluminides

1996 ◽  
Vol 460 ◽  
Author(s):  
W. O. Soboyejo ◽  
A. B. O. Soboyejo ◽  
Y. Ni ◽  
C. Mercer
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Titanium Aluminides ◽  
Regression Equations ◽  
Combined Effects ◽  
Wide Range ◽  
Elongation To Failure ◽  
Prediction Of Mechanical Properties

In a recent paper, Mercer and Soboyejo [1] demonstrated the Hall-Petch dependence of basic room- and elevated-temperature (815°C) mechanical properties (0.2% offset strength), ultimate tensile strength, plastic elongation to failure and fracture toughness) on the average equiaxed/lamellar grain size. Simple Hall-Petch behavior was shown to occur in a wide range of extruded duplex α2-γ alloys (Ti-48A1, Ti-48Al-1.4Mn Ti-48Al-2Mn and Ti-48Al-1.5Cr). As in steels and other materials [2–5], simple Hall-Petch equations with were derived for the above properties [1]. However, the Hall-Petch equations did not include the effect of other variables that can affect to the basic mechanical properties of gamma alloys. Multiple linear regression equations for the prediction of the combined effects of several (alloying, microstructure and temperature) variables on basic mechanical properties temperature are presented in this paper.

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