EXPERIMENTAL RESULTS OF THE TEMPERATURE EFFECT OF CRYOLITHOZONE SOILS ON THEIR PHYSICAL AND MECHANICAL PROPERTIES

2021 ◽  
Vol 10 (4) ◽  
pp. 197-207
Author(s):  
Sergey Rudov ◽  
Vladimir Shapiro ◽  
Igor Grigorev ◽  
O. Kunitskaya ◽  
Olga Grigoreva ◽  
...  

Establishing the regularities of the temperature influence of frozen soils on their physical and mechanical properties makes it possible to make more accurate estimates of the parameters of the interaction process of forest machines and skidding systems with the soil mass when performing logging operations with predetermined static loads. An adequate assessment of the state of the edge part of frozen soil mass is the basis for the formation of initial conditions when calculating the parameters of the destruction of the stress-deformed frozen soil layer, the processes of its compaction and deformation under the influence of static loads arising from the operation of various forest machines and skidding systems. The article presents methodology, hardware and the results of data processing obtained in field experimental studies to determine the effect of frozen soil temperature on its strength and deformation properties. To reveal the regularities of the change in soil temperature in depth, as well as in order to take soil samples for testing the mechanical properties in depth, soil benches with an area of 1×1 m and a depth of up to 1.0 m were opened. Sections were investigated in three areas with a predominance of: permafrost pale brown soils with sandy loam soil base; humus-carbonate soils with a loamy base; cryozem gley soils with a clay base. Soil temperature was measured near the ledge surface with a HI 98501 Hanna soil electronic thermometer (Germany) with a resolution of 0.1°C and an error of ± 0.3°C. The temperature value was measured as the depth increased with the help of a penetrating thermometer probe in the control holes along the depth of the ledge with a step of 0.1 m

2018 ◽  
Vol 7 (3.2) ◽  
pp. 236
Author(s):  
Grigoriy Masiuk ◽  
Oleksandr Yushchuk ◽  
Andrii Paschenko

The article is devoted to the experimental studies of the stress and strain state of the two-pass reinforced concrete beams under the influence of low-cyclic repeated and alternating loads. Based on the results of experimental studies, the effect of low-cyclic repeated and alternating loads on the change of the stress and strain state of continuous reinforced concrete beams has been established. In the course of testing the sample, it was found that the stress and strain state of the beams under the action of the above mentioned loads is significantly different from the stress and strain state of the beams under the action of nonalternating static loads, namely, the decrease of the bearing capacity, the increase of the deflections and the width of the cracking. All this is due to the change in the physical and mechanical properties of concrete in response to the above-mentioned loads on experimental.  


2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.


2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.


2019 ◽  
Vol 974 ◽  
pp. 181-186
Author(s):  
V.A. Perfilov ◽  
V.V. Gabova ◽  
Inessa A. Tomareva

The effect of superplasticizing, foam agents, various fiber aggregates on the physical and mechanical properties of cellular concrete has been studied. The article covers the results of experimental studies conducted to determine the effect of foam agents PO-6 and PB-2000, as well as polymeric and basalt fiber on the pore structure of foam concrete. The dependence between the change in density and strength of cellular concrete and the structure of its pore space has been determined.


Author(s):  
Хафизов ◽  
Kamil Khafizov ◽  
Хафизов ◽  
Ramil Khafizov

A similarity criteria were reveled to determine the dependence of maximum pressure of the tractor wheel on the soil on the basis of the use of similarity theory. Each similarity criterion includes several parameters, characterizing the tractor, its propeller and physical and mechanical properties of the soil. The similarity criteria is taken as factors in the multivariate experiment. Multifactorial experimental studies were planned and carried out. We used Statistics Toolbox subsystem of Matlab computer mathematics system for processing the results of experiments. As a result of statistical processing of the experimental data by the equation we obtained a dependence of maximum pressure of the tractor wheel on the soil from tractor parameters, and physical and mechanical properties of the soil. Statistical data on the equations, such as - multiple correlation coefficient, Fisher’s criterion, Student’s criterion, indicate the significance of equations of the experiments variants, as well as the significance of the coefficients of the regression equations.


Author(s):  
N. I. Chaban

Research of new methods and technologies of non-destructive control of change of long-term metal structures is an actual task of the present. In this article the methodology and results of experimental studies, the main aim of which is to determine the correlation between the intensity of structural noise in the material determined by failure detectors based on ultrasonic field-induced phase grating and the physical and mechanical properties of steels are presented.


Author(s):  
Fery Erawan ◽  
Emi Sukiyah ◽  
Johanes Hutabarat ◽  
Adjat Sudradjat

Bintan Island is a part of Riau Islands Province. On this island, the capital city is Tanjungpinang. The compliance of public facilities such as landfill waste is a priority in this city. Landfill design that suitable in this area is a sanitary landfill system. The soil layer uses to cover the waste in this landfill system. The closure did gradually avoid the disruption of waste processing. The type of soil for its landfill cover has to be able to control the leachate. It controlled by the permeability of the soil. The methods used in this study are the analysis of the physical and mechanical properties of soil. Rock and soil samples are obtained systematically through trenching. Sampling-based on changes in physical properties of soil that reflect its mechanical properties. A probabilistic approach used to solve the problems and to get accurate results. The geomorphology of the study area divided into four units. They are very flat terrain, flat terrain, slightly steep hills, and steep hills. The sample used for the study is undisturbed soil. Analysis of the physical and mechanical properties of soil shows the types of soil, such as SW, GM, MH-OH, and CH. However, MH is the most dominant type of soil. Each of the soil types represents a certain degree of weathering. The degree of weathering in the study area varies from the III degree to VI degrees. Rocks are weathering form clay mineral, which compiles the soil. Clay mineral in the soil layer is varied from quartz, illite, kaolinite, gibbsite, goethite, and hematite—the impact of the swelling of clay. The swelling of clay in the study area ranged from low to high. The properties and composition of the soil are affected by the permeability value.


2020 ◽  
Author(s):  
Maryna Leshchyshyn Mykolaivna ◽  
Svitlana Stepanivna Garkavenko ◽  
Antonina Ivanivna Babich

Determination of values and dependencies of deformation and physical and mechanical properties of materials of shoe models and finished products. According to the results of theoretical, analytical and marketing research, a number of experimental tests of materials have been carried out to prove the practical significance of the work, namely tests for: deformation of the vamp part of the product, uniaxial and biaxial stretching, bending, dry and wet friction, adhesion, elongation and tearing. There has been established the nature of the distribution of the total elongations of the samples of the vamps cut from different areas of the leather, as well as the ability of the leather material to be formed when improving the shape of the product or changing the shape of the shoetree. The processes of deformation of the vamp part of shoe blanks, physical and mechanical properties of different groups of modern materials and values analysis of similarity of their deformation properties have been studied. There has been created a working model-transformer for carrying out preliminary measurement of clients’ feet at the individual order. The expediency of these works has been proved experimentally. A working version of a model-transformer for foot measurements has been made and as a result of the works approbation, a sample of shoes has been made. The ergonomic properties of the manufactured footwear have been improved due to the use of materials with enhanced physical and mechanical properties. The article investigates the deformation of the most vulnerable vamp part of the men's model of a typical model, as well as the physical and mechanical characteristics of leather materials for manufacturing models and shoes of this type. Providing high quality and comfort of footwear, accuracy of parameters selection of foot measurement, zones of beams and achievement of form stability of footwear with a top from genuine leathers has been predicted.


2021 ◽  
pp. 43-51
Author(s):  
А. С. Паршин ◽  
С. І. Арабулі ◽  
А. Т. Арабулі

Assessment of the providing level of hotel facilities by quality terry towels based on a comprehensive study of the operational properties of terry textile fabrics. Methodology. Theoretical and experimental researches are based on the basic principles of textile materials science. During experimental studies, modern methods were used to determine the physical and mechanical properties of textile materials, as well as methods of mathematical planning and statistical processing of the experimental results. Results. The state and norms for the provision of hotel facilities in Ukraine with terry towels are given. The assortment of hotel terry towels has been analyzed. The main factors of the formation of a modern assortment of textile materials for hotel terry towels are considered. The focus is on the classic range of double nap terry fabrics for hotel towels. The analyses of the physical and mechanical properties of modern fabrics for hotel towels are present. Indicators characterizing the interaction of textile with liquid moisture have been experimentally determined. The paper presents the results of determining the wear resistance of fabrics after 1, 5 and 10 cycles "wash-ironing". Scientifi c novelty. The data of the physical and mechanical properties of the classic assortment of textile materials for hotel terry towels are systematized. It has been experimentally proven that the assortment of cotton terry textile materials, which is currently available on the Ukrainian market and is used for the manufacture of hotel terry towels, provides a high level of comfort and durability of towels. Practical value. The modern assortment of textile materials for hotel terry towels is analyzed, taking into account the peculiarities of the operational situation of consumption.


2021 ◽  
Vol 2021 (11) ◽  
pp. 51-59
Author(s):  
Nikolay Kurnosov ◽  
Aleksandr Tarnopol'skiy ◽  
Yuliya Nakashidze

Work objective is to solve the urgent problem of increasing the tightness and reliability of pressure couplings during their operation under dynamic loads. Theoretical and experimental studies assessing the impact on the tightness due to roughness nature of mating surfaces and three types of coatings: soft, double-layer and hard have been undertaken. The joints were tested under the influence of axial cyclic load and torque on a bench for accelerated testing. It is established that tightness of pressure couplings during operation under dynamic loads significantly depends on the parameters of microgeometry and physical and mechanical properties of the mating surface material that determine their actual contact area. Recommendations for preparing the surfaces of parts before pressure coupling assembling have been developed. It is proved that the use of regular microrelief and soft galvanic coatings of mating surfaces have a significant effect on the tightness of pressure couplings.


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