Cross-Section Configuration Coefficient in the Zhurkov’S Generalized Equation

2021 ◽  
pp. 73-82
Author(s):  
В. М. Данилов ◽  
А. О. Корнеева ◽  
А. Б. Бондарев ◽  
Т. Н. Стородубцева
Keyword(s):  
Cross Section ◽  
Construction Material ◽  
Construction Materials ◽  
Thermal Fluctuation ◽  
Thermal Fluctuations ◽  
Physical Structure ◽  
Generalized Equation ◽  
Theoretical Concepts ◽  
Fluctuation Relations ◽  
Layer Composite

Постановка проблемы. Исследование долговечности строительных материалов с термофлуктуационной позиции является наиболее сложным, но и в тоже время наиболее адекватным методом. Ввиду того, что данная концепция является нечувствительной к изменениям физической структуры, возникает необходимость учета не только материала, но и конфигурации конструкции. Необходимо провести сравнение механизма разрушения при различных вариантах сечения для двух структурно отличающихся элементов - поливинилхлорида (ПВХ) и древесины. Результаты. Для элементов ПВХ и дерева составного сечения в два слоя без специальных связей получен одинаковый коэффициент k = 2. Для элементов составного сечения в три слоя без специальных связей получен коэффициент с интервалом k = 3,5…5,5, что требует дальнейшего уточнения. Выводы. На основе проведенного исследования теоретически обоснованы и экспериментально выявлены закономерности деформирования и разрушения ПВХ-элементов цельного сечения и составного сечения без специального соединения в два и три слоя. Определение термофлуктуационных зависимостей позволяет приблизить теоретические представления о работоспособности строительного материала в конструкции к реальным условиям. Statement of the problem. Studying the durability of construction materials in the aspect of thermal fluctuations is the most complicated, yet the most appropriate method. Considering that this concept does not take into account the changes of the physical structure, it becomes necessary to consider not the material alone but also the configuration of the structure. Therefore it is necessary to make a comparison of two structurally different elements - PVC and wood. Results. The coefficient of the 2-layer composite cross-section (no special connection) is the same for the PVC and wood elements: k = 2. The derived coefficient of the 3-layer composite cross-section (no special connection) is within the following range: k = 3,5…5,5, which requires a more precise definition. Conclusions. Based on the above experiment, we have theoretically established and experimentally confirmed the regularities of deformation and destruction of PVC elements of the 2 and 3-layer solid and composite cross-section without a special connection. Determining the thermal fluctuation relations allows us to bring theoretical concepts of the capacity of the construction material in a structure closer to actual conditions.

scholarly journals Thermal fluctuation constants of PVC elements of different cross-sections

2021 ◽  
Vol 263 ◽  
pp. 01016
Author(s):  
Vladislav Danilov ◽  
Alexander Erofeev
Keyword(s):  
Initial Data ◽  
Cross Section ◽  
Cross Sections ◽  
Building Material ◽  
Building Materials ◽  
Thermal Fluctuation ◽  
Physical Structure ◽  
Composite Section ◽  
Adequate Method

Consideration of the durability of building materials from a thermal fluctuation position is the most difficult, but at the same time the most adequate method now. Since this concept is insensitive to changes in the physical structure, it becomes necessary to consider not only the material, but also the configuration of the structure. This will make it possible to bring the simplified theoretical ideas about the performance of a building material in a structure closer to real conditions. Thus, the aim of the work is to compare the destruction mechanism of PVC sheet elements of solid section and composite section from the thermal fluctuation position. To achieve this goal, the initial data for finding thermal fluctuation constants (durability of PVC plates at non-critical stress) were determined by an experimental method. Based on the initial data, the thermal fluctuation constants for each section were determined by the graphic-analytical method. During the comparative analysis, it is proposed to introduce a coefficient into the Zhurkov’s equation, which will consider the configuration of the section. It was also determined that for PVC sheet elements of composite cross-section in two layers, this coefficient is kc = 2. Considering the configuration of the cross-section when determining the thermal fluctuation dependences will increase the quality of predicting the durability of the building material.

scholarly journals Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4014
Author(s):  
Karol Prałat ◽  
Andżelika Krupińska ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Construction Material ◽  
Construction Materials ◽  
Optical Microscope ◽  
Passive Layer ◽  
Initial State ◽  
Time Intervals ◽  
Significant Deterioration ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Steel Heat

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

A Simulation of a Generalized Thermal Radiating Fin

SIMULATION ◽  
1964 ◽  
Vol 2 (6) ◽  
pp. 19-22
Author(s):  
M.T. Janicke ◽  
L.C. Just
Keyword(s):  
Power Plant ◽  
Cross Section ◽  
Construction Material ◽  
Heat Removal ◽  
Thermodynamic Cycle ◽  
Space Applications ◽  
Maximum Heat ◽  
Electrical Systems ◽  
Extra Weight ◽  
The Relationship

The purpose of this paper is to provide a method for designing radiator fins with maximum heat removal capability per pound of construction material. This problem becomes important when radiators are designed for space applications, since all of the heat from the thermodynamic cycle must be removed by means of radiation. Moreover, space transportation vehicles are seriously limited as to payload, so that weight must be saved in all parts of a power plant. An increase in the output of a space power plant does not change the reactor, turbine, and generator as much as the radiator, with the result that, for megawatt electrical systems, the radiator is the dominant weight contributing component. A radiator could be built of coolant tubes alone, but this increases certain hazards. Meteor punctures can occur, so that the amount of area devoted to coolant tubes should be reduced as much as pos sible. Fins attached between the tubes can perform this function by extending the heat radiating surface. The extra weight of the fins is partly compensated for by a reduction in tubes and coolant. Extra savings can occur if the weight of the fin is minimized; optimum thickness, length, and cross section must be found. This paper studies the relationship between fin cross- section and radiating power.

A theory of incoherent scattering of radio waves by a plasma

1960 ◽  
Vol 259 (1296) ◽  
pp. 79-99 ◽  
Keyword(s):  
Cross Section ◽  
Thermal Fluctuations ◽  
Incoherent Scattering ◽  
Doppler Broadening ◽  
Radio Waves ◽  
Central Frequency ◽  
Resonance Effects ◽  
Doppler Shifts ◽  
The Mean ◽  
Free Plasma

A theory is developed which describes the scattering of radio waves by the random thermal fluctuations of electron density in a collision-free plasma. The frequency spectrum, as well as the amplitude, of the scattered radiation is calculated. Particular attention is paid to the part of the spectrum which corresponds to small Doppler shifts, this being the region of greatest significance in connexion with the phenomenon of incoherent scattering from the ionosphere. The calculations are based on a generalized version of Nyquist’s noise theorem, and they lead to the following conclusions: (1) The mean scattering cross-section for the ionosphere is equal to that which would exist if each of the electrons scattered independently with a cross-section of one-half the classical Thomson cross-section. (2) The mean Doppler broadening of the scattered signal corresponds roughly to the speed of the ions rather than to that of the electrons. (3) The spectral shape of this signal is not Gaussian. There is a mild maximum in the spectrum away from the central frequency, as can be seen in figure 1. (4) Plasma resonance effects contribute only negligibly to the scattering for frequencies currently of interest.

EFFECT OF YELLOW LOESS ON ODOROUS GAS ADSORPTION AND ECOTOXICITY TEST USING DAPHNIA MAGNA

2021 ◽  
Vol 16 (1) ◽  
pp. 103-114
Author(s):  
Hongseok Jang ◽  
Boram Lee ◽  
Seungyoung So
Keyword(s):  
Daphnia Magna ◽  
Cement Mortar ◽  
Construction Material ◽  
Objective Assessment ◽  
Test Chamber ◽  
Construction Materials ◽  
Ecotoxicity Test ◽  
Lamellar Crystal ◽  
Exposure Test ◽  
Natural Materials

ABSTRACT To minimize damage caused by harmful substances released from artificial construction materials, there has been increasing interest in eco-friendly houses constructed with natural materials. Among natural materials, yellow loess is South Korea’s most representative eco-friendly construction material, with high purification performance for indoor use. However, there has been no objective assessment of yellow loess’s performance at purifying indoor air. In this study, internal pores were found in yellow loess that were of a lamellar crystal structure consisting of bonds of silica and alumina plates, and there was a high negative charge on the loess surface; these might have contributed to the excellent performance of yellow loess in adsorbing odorous gas. There was also an exposure test using Daphnia magna to determine the eco-friendliness of yellow loess compared with that of cement mortar. Results showed the survival of Daphnia magna was longer in the indoor environment of a test chamber with higher concentration of ammonia wherein yellow loess was placed. EC50 (median effective concentration, the concentration that caused death of 50% of bio-specimens) value of 19 ml of ammonia (0.1% solution), which was three times more than EC50 value of 6 ml of ammonia of the same area of cement mortar.

Study of the Effect of PP and LDPE Thermoplastic Binder Addition on the Mechanical Properties and Physical Properties of Particulate Composites for Building Material Application

2019 ◽  
Vol 964 ◽  
pp. 115-123
Author(s):  
Sigit Tri Wicaksono ◽  
Hosta Ardhyananta ◽  
Amaliya Rasyida ◽  
Feisha Fadila Rifki
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Building Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Waste Recycling ◽  
Plastic Waste ◽  
Particulate Composites ◽  
Water Absorbability

Plastic waste is majority an organic material that cannot easily decomposed by bacteria, so it needs to be recycled. One of the utilization of plastic waste recycling is become a mixture in the manufacture of building materials such as concrete, paving block, tiles, roof. This experiment purpose to find out the effect of addition of variation of LDPE and PP thermoplastic binder to physical and mechanical properties of LDPE/PP/Sand composite for construction material application. In this experiment are using many tests, such are SEM, FTIR, compression strength, density, water absorbability, and hardness. the result after the test are the best composition of composite PP/LDPE/sand is 70/0/30 because its have compression strength 14,2 MPa, while density value was 1.30 g/cm3, for the water absorbability is 0.073%, and for the highest hardness is 62.3 hardness of shore D. From the results obtained, composite material can be classified into construction materials for mortar application S type with average compression strength is 12.4 MPa.

New Lightweight Construction Material: Cellular Mat Using Recycled Plastic

2013 ◽  
Vol 594-595 ◽  
pp. 503-510
Author(s):  
T.I.T. Noor Hasanah ◽  
D.C. Wijeyesekera ◽  
Ismail bin Bakar ◽  
Wahab Saidin
Keyword(s):  
Cellular Structure ◽  
Construction Material ◽  
Construction Materials ◽  
Base Material ◽  
Social Benefit ◽  
The Body ◽  
Lightweight Construction ◽  
Ground Condition ◽  
Application Specific ◽  
Design And Construction

Applications of lightweight construction materials enable the design and construction in challenging, difficult and demanding scenarios. Construction materials with enhanced stiffness as in sandwich panels, large portable structures and floating foundations are examples of such materials. The advent of cellular structure technology has actively introduced innovation and enabled design and construction, meeting engineering requirements such as in the construction of the body of air crafts. Cellular mat structures present in the minimum, triple benefits in being lightweight, load sharing and minimising non-uniform deformation. This paper further explores the use of recycled plastic waste as the base material for an innovative geomaterial. The combination of cellular structure, mat structure and use of recycled waste material is a desirable development in manufacturing. Paper also outlines the techno social benefit of adopting such material in construction. Other application-specific benefits related to cellular mats are those like noise reduction, energy absorption, thermal insulation, mechanical damping. This paper specifically presents the development of a new multifunctional lightweight material is been proposed as an invective innovation for highway construction on challenging ground condition.

scholarly journals Application of Wall and Insulation Materials on Green Building: A Review

2018 ◽  
Vol 10 (9) ◽  
pp. 3331 ◽  
Author(s):  
Hao Wang ◽  
Pen-Chi Chiang ◽  
Yanpeng Cai ◽  
Chunhui Li ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Construction Material ◽  
Construction Materials ◽  
Green Building ◽  
Development Trend ◽  
Plant Fibers ◽  
Sustainable Resources ◽  
Insulation Materials ◽  
Green Construction ◽  
Wall Materials

The construction materials utilized in the building sector have accounted for a large amount of natural resource and energy consumption. Green building, which has developed over three decades, can be regarded as a management and technical approach for building and construction sectors to achieve resource and energy sustainability in building sectors. Therefore, the development and deployment of green construction materials play an important role in the green building field due to the contribution of sustainable resources and energy. To realize the barriers of energy and resources utilization on green building, the development trend, application, and some case studies on wall materials and thermal insulation materials are described. A summary of plant fibers, recycled wastes, and photochromic glass is developed to show applications of green construction materials, which contributes to sustainable development. The challenges and barriers from business, technical, and policy aspects are also reviewed. Finally, perspectives and prospects of green construction material life-cycle framework are illustrated. This paper presents a snapshot review of the importance of wall materials and thermal insulation materials from the point of view of energy and resources consumption.

scholarly journals A Prototype Expert System for the Selection of Road Construction Materials

2007 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
S. Hassim ◽  
K.T. Teh ◽  
R. Muniandy ◽  
H. Omar ◽  
A. Hassan
Keyword(s):  
Expert System ◽  
Knowledge Base ◽  
Material Selection ◽  
Construction Material ◽  
Construction Materials ◽  
Road Construction ◽  
Statistical Testing ◽  
Factors Affecting ◽  
Microsoft Access ◽  
Programming Tool

A prototype for an expert system in road construction material selection system, which is based on the outcomes of Friedman and multiple comparisons statistical methods was developed. The outcomes were acquired through questionnaires from selected pavement experts. The factors affecting pavement materials under each particular site condition were incorporated into the specific rules of the system. The system knowledge-base was extracted from the statistical testing outcomes and then rearranged and compiled prior to the development of the system. Visual Basic 6.0 was adopted as the programming tool for development of the system, while the knowledge-base of the separate system was kept in Microsoft Access 2000. The prototype expert system can be used to emulate part of the professional reasoning capabilities based on the knowledge of a pavement expert or a specialist to solve problems on materials selection. The system can help road designers to improve their professional ability to evaluate all available materials even before carrying out any laboratory tests.

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