bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical and computer modeling in the design of steel rod structures
Authors: Vasilkin A 
Published: January 2020

Abstract
The article considers the problem and search solution of an optimal variant of the design of steel structures based on the use of computer technology and mathematical modeling. As a method of search of the optimal solution, the method of parametrical optimization is used. The application of the method is illustrated on the example of a flat rod design - a truss construction. The variable parameters were selected to build a gruph for changing the target function. The novelty of the study lies in the fact that as a criterion of optimality, the cost of its production was adopted, at that time, how often is the weight of the structure taken. As a result of the conducted research it was found that the difference in production cost at application of different types of outlines of belts makes up to 20%. For criteria of an optimality metal consumption and production cost were received various versions of the optimal solution that tells about the important role of the chosen criterion and the need of the accounting of bigger quantity of elements to compose the optimality criterion. Efficiency and expediency of use of computer technologies to design steel structures is shown. That gives the engineer necessary information for adoption of reasonable design decisions on the basis of the analysis of alternative options.
The longitudinal-transverse bending of multilayered concrete rods taking into account the influence of gravity
Authors: Nemirovskii Yu V , Tikhonov S V 
Published: January 2020

Abstract
The paper considers the problem of longitudinal-transverse bending of a multilayered concrete rod taking into account the influence of gravity. The law of deformation of each layer of the rod is adopted in the form of approximation by a polynomial of the second order. The main purpose in this work is to study the influence of gravity on the ability of the rod to withstand the applied loads. In this work, the achievement by the maximum deformation the limit allowable value in one or several layers of the rod under tension or compression, corresponding to the points of transition to the descending branch in the deformation diagram, is accepted as a criterion for the conditional limit state. The approximate solutions of these problems are found by the Bubnov-Galerkin method.
Deformation of beam structures in an internal explosion
Authors: Gorev V A 
Published: January 2020

Abstract
The paper considers the deformation of a hinged beam exposed to the action of an explosive load at the initial stage of an internal explosion, when the excess pressure increases according to the third degree of time. With this law of load change, the rate of its increases all the time, which leads to an increase in dynamism. Analytical expressions are obtained for the deformation value and its velocity, both at the growth stage and at the pressure drop. The case of transition of elastic deformation to plastic deformation both at the stage of load growth and decline is considered. The decline was approximated by a linear function of the start time of the decline. Calculations have shown that the deformation rate increases significantly towards the end of the lifting stage. If plastic deformation occurs at the stage of lifting close to its end, the coefficient of plasticity is close to 10 or more. If plastic deformation occurs at the stage of decline, the coefficient of plasticity varies between 1.4÷2.
Calculation and experimental substantiation of optimal sizes of large-size tanks filled with bulk material
Authors: Fedorova T G 
Published: January 2020

Abstract
The numerical calculation of elastic-plastic deformation and limiting States of shell structures of large-size tanks filled with bulk material is carried out. The solution of a three-dimensional geometrically and physically nonlinear problem is based on the finite element method and an explicit cross-type time integration scheme. The critical load at which the tank loses stability is determined. The influence of the length of the tank on its stability is investigated.
Analytical methods of theoretical physics in the modeling of building structures
Authors: Gulkanov A , Modestov K 
Published: January 2020

Abstract
In this paper, on the basis of the variational principle of the least Hamilton action, the field-theoretic Lagrange equations of the 2nd kind are derived in the presence of a dependence of the density of the Lagrange function on the higher derivatives. On the basis of the obtained equations, written in terms of variables that most fully reflect hypotheses and used assumptions, the equations of continuum mechanics are obtained and the Timoshenko, Rayleigh and Euler-Bernoulli beam models are calculated. It is shown that the method used leads to a more efficient method of obtaining partial differential equations describing the dynamics of deflection of beams. The possibility of taking into account the distributed load and the elastic base in the Lagrangian formalism is noted. The possibility of further development of analytical and theoretical-physical methods in application to mathematical modeling of building structures is analyzed.
Influence of geothermal environment on the corrosion fatigue behaviour of standard duplex stainless steel X2CrNiMoN22-5-3
Authors: Wolf Marcus , Pfennig Anja 
Published: January 2020

Abstract
In the geothermal environment corrosion fatigue may severely lower the lifetime expectancy of high alloyed steels. Therefore, the corrosion fatigue (CF) of duplex stainless steel X2CrNiMoN22-5-3 was investigated in the Northern German Basin electrolyte at 369 K using a specifically designed corrosion chamber. Although the failure mechanism is independent of surface roughness (low scatter ranges technical surface: TN=1:1.35, polished surface: TN=1.1.95), the life expectancy in purely alternating axial cyclic load to failure was clearly related to surface finish and applied stress amplitude. Specimen with technical surfaces tested at high stress amplitudes (>275 MPa) lasted longer (cycles to failure: P50% at Sa 300 MPa=5x105) than specimen with polished surfaces (cycles to failure: P50% at Sa 300 MPa=1.5x105). When applying a protective potential a significant increase of CF life range from 4.7 x 105 (free corrosion potential) to 107 cycles (potential range from USHE = –450 to – 900 mV) was observed. Microstructural analysis of the CF damage revealed horizontal grain attack within corrosion pit cavities, multiple fatigue cracks and preferable deterioration of austenitic phase. At low stress pitting is the initiating crack growth process whereas at high stress amplitudes the formation of micro cracks is reason for crack propagation and failure.
Interaction of whole fiber and destroyed neighbour fiber in reinforced plastic
Authors: Turusov R , Bogachev E , Andreev V 
Published: January 2020

Abstract
Composite materials, both on the basis of polymeric binder, and other materials, for example, concrete are widely distributed. The paper considers the case of longitudinal location of elements. The paper deals with the question the intensity of the adhesive interaction, of course, with the true strength of the adhesive bond. To study the interaction of two adjacent fibers, whole and broken in work, it is proposed to use the concept of a contact layer [1 – 4]. To study the interaction two adjacent fibers, whole and torn, we propose use the concept of contact layer. This anisotropic layer has a certain thickness, equal to the length of the bonds, the shear modulus in the contact plane, and the Young’s modulus along the rod-bonds. In fact, it is an anisotropic continuous medium. When solving one-dimensional problems, the shear modulus and thickness of the contact layer are combined into one parameter, whose influence is decisive on the distribution pattern and stress intensity near the edge. This parameter can be determined quite easily from a macro experiment.
Stability of Ladders when Working at heights and Safety while performing this type of work
Authors: Pham N T , Vasilenko V V 
Published: January 2020

Abstract
The analysis of industrial injuries when working at heights is conducted. Statistics show that a fall from a height takes more than 30% of the total number of accidents. Operations with the help of ladders are the most common type of works at heights. However, the ease of installation and use of ladders often leads to the fact that the persons performing the work do not pay enough attention to safety. The aim of the work was to improve the safety in operation at heights with the use of ladders inclined to the horizontal surface. An important prerequisite for the safe use of ladders is to ensure their stability. There were analyzed the most common devices used to increase the stability of ladders. The issue of applying a lifeline system attached to a ladder (if the ladder is affixed to a building or other structure), when working with a ladder at heights of more than 1.8 m, is considered. The inferiority of this issue is shown in the current regulatory documents. It was proposed to revise the relevant requirements in the regulatory documents on the possibility of using a lifeline system attached to the ladder, requirements for the durability of the ladders and methods of their testing.
Low-cycle Fatigue of High Processible Aluminum Alloy Flat Products from Alloyage System Al-Mg-Si
Authors: Shuvalov Aleksandr , Katanina Alla , Kornev Oleg , Kovalev Mikhail 
Published: January 2020

Abstract
Resistance to low-cycle fatigue of hot-rolled plates manufactured from alloyage system Al-Mg-Si alloy 6082 is researched. Cyclic stability of alloy and cyclic proportional elastic limit were defined during tests of specimens without cracks loaded along the rolling direction using curves of cyclic strain and their generalization. Properties used for design of prefabricated structures from thick aluminum plates from alloy 6082 operating in the conditions of low-cycle fatigue are received.
Strength, chloride resistance and corrosion reinforced of High-strength concrete
Authors: Xuan Hung Ngo , Van Lam Tang , Bulgakov B I , Alexandrova O V 
Published: January 2020

Abstract
Typical low-calcium fly ash (LC-FA) and silica fume SF 90 (SF-90) was used as a binder in the mixture of high-strength concrete (HSC), replacing (20-40)% and (5-15)% of the weight of Portland cement, respectively. The slump of fresh HSC mixtures, compressive strength, density and water absorption of HSC samples were investigated. Applying the standard NT Build 356 combined with standard ASTM C1202-97 for assessment of the chloride resistance and the corrosion resistance reinforced of tested concrete produced using high-calcium fly ash and Silica fume was studied in this work. The results show that the compressive strength of examined concrete decreased with increasing LC-FA content and was lower than the concrete used mix control, while the compressive strength of concrete mixtures with SF-90 at 5%, 10% and 15% by mass cement was higher than the sample tested with mix control and significantly higher than the LC-FA concrete mixtures. LC-FA and SF-90 in HSC decreased the charge passed and tends to decrease, while the times of initial crack of the test specimens gain increased with increasing LC-FA and SF-90 contents. The chloride ion penetrability of HSC is very low.
Effect of the soil pressure and that of filtration forces on a triangular retaining wall
Authors: Agakhanov E , Agakhanov M , Begov N 
Published: January 2020

Abstract
The filtration forces considered as the forces determining the form and the performance characteristics of full-scale hydro-engineering gravity structures have a significance comparable with that of the main effects: the hydrostatic pressure and the own mass of the structure. The examples of determination of the stress state caused by filtration forces through the modelling method include the recommendations on the replacement of the aforesaid effects by the surface loadings applied to the gravity centre of their projections. This method reduces the accuracy of the results and requires (like with the construction of backpressure lines) the tests of many models. The authors carried out the modelling of the effect of the soil pressure and that of filtration forces in accordance with the modelling methodology based on the equivalence of effects. The article contains a solution for a retaining wall with a triangular cross-section under the effect of the soil pressure on the vertical side and that of volume filtration forces.
Foamed concrete containing various amounts of organic-mineral additives
Authors: Kim Dien Vu , Cong Ly Nguyen , Van Lam Tang , Bazhenova S I 
Published: January 2020

Abstract
The present study evaluated the combined effects of organic-mineral additive based on a superplasticizer SR 5000F and the active mineral additive Fly Ash, Blast Furnace Slag and Silica Fume SF-90 on properties of foam concrete (FC). The calculation of mixture proportions of FC is applied in accordance with the absolute volume method. Besides, the compressive strength and flexural strength of foam concrete are determined by Russian standard GOST 10180-2012. The results from experiments show that flexural and compressive strength of the FC obtained respectively, from 3.25 to 5.08 MPa and from 13.91 to 26.87 MPa. The use of an organic-mineral additive in the mixture was led to increasing the compressive and flexural strength of foam concrete at the age of 28 days, respectively, from 8% to 93% and from 6% to 56%. The relationship between compressive strength and curing age, compressive and flexural strengths of the FC were also determined in this investigation. The results of this study demonstrated that the use of appropriate amounts of fly ash and blast furnace slag to partially replace natural sand could produce eco-friendly foam concrete, which has many positive environmental impacts.
The influence of stress state, density and moisture on the dynamic properties of soil cement samples created by the method of deep soil mixing
Authors: Ter-Martirosyan A Z , Sobolev E S 
Published: January 2020

Abstract
The transformation of the properties of the bases by the method of deep soil mixing allows the construction of buildings and structures on sites with soft soils. As a rule, adverse geological conditions are accompanied by the presence of dynamic effects on the designed buildings. The objective of this research is to forecast changes in the mechanical properties of the base under dynamic loads. The object of study is the propagation velocity of elastic shear waves, since these parameters significantly affect the calculations of deformations and stability of earthquake-resistant industrial and civil buildings and structures, as well as objects of energy and transport construction. The paper contains a review of similar studies, on the basis of which the conclusions obtained during the experiments are further generalized. Based on the analysis of the results of laboratory tests performed by the authors of this work, by the method of low-amplitude torsion vibrations in a resonant column in the anisotropic triaxial compression mode, the influence of the density of soil cement samples, humidity, and additional load on the propagation velocity of elastic transverse waves is estimated. The paper provides a description of the essence of the research method, a review of the equipment on which special laboratory tests were performed. The tests were carried out on samples of unbroken soil cement taken from the base of a nuclear power plant (NPP) under construction. Dried samples of soil cement were investigated, and tests were carried out at full water saturation and at a given humidity. The anisotropic stress state of soil cement samples during triaxial tests in a resonance column was due to the features of the base of the designed NPP. Studies have shown that the most significant factor affecting the shear wave velocity is the additional vertical load. It is noted that with increasing density, the velocity of the shear waves decreases. Humidity is directly related to the density of soil cement and the amount of water in the pores, so the assessment of its effect on the dynamic properties of soil cement is similar to the effect of changes in density.
Vibration reduction techniques for Rapid Impulse Compaction (RIC)
Authors: Dobrzycki Przemysław , Kongar-Syuryun Cheynesh , Khairutdinov Albert 
Published: January 2020

Abstract
New investments on anthropogenic soils bring the necessity for reliable and sustainable soil improvement methods. When the fill contains mainly non-cohesive soils and large thickness of material layers is considered, its physical properties can be improved by means of Rapid Impulse Compaction technology. Large energy of every impulse imposed by the mass of the hammer and drop height (with acceleration) makes it possible for relatively fast completion of works but causes large noise and severe vibrations. Environmental impact on adjacent structures may also cause some destruction and form the basis for legal claims. When serious damages appear in neighbouring buildings and structures, complains and claims are inevitable. Reduction of this negative impact may be achieved by means of technology calibration or other active and passive measures. The paper presents the description of that problem, some literature review and a case study describing how the intensity of vibrations may be to some extent reduced by means of hammer drop height reduction and digging a trench around the worksite.
Comparison of assessing the filtration coefficient from laboratory tests with correlation results determined from CPTu test for coarse-grain soil
Authors: Dudek Nikola , Bagińska Irena 
Published: January 2020

Abstract
Filtration coefficient is a basic parameter to assess hydrogeological features of foundation soil and also the material to be built into geoenginering structures. It can be determined from laboratory testing, empirical formulae based on simple laboratory tests, and also from direct or indirect field tests. Each of these method may lead to different values of filtration coefficient. The paper is focused on determining filtration coefficient of coarse-grain soil with several techniques. Direct results from laboratory testing were referred to the indirect evaluation based on grain size analysis and on static sounding CPTu test.
Mechanical and barrier properties of Tapioca/PVA composite films reinforced with pineapple leaf nanocellulose
Authors: Listyarini A , Fauzia V , Imawan C 
Published: January 2020

Abstract
Studies on mechanical and barrier properties of Tapioca/PVA composites reinforced with pineapple leaf nanocellulose have been done to obtain an alternative new biodegradable label for freshness label of smart packaging for food. The aim of this research is to investigate changes of mechanical and barrier properties of Tapioca/PVA/Nanocellulose compared with Tapioca/PVA composite. Composition of Tapioca/PVA was 50:50 with nanocellulose concentration vary from 1, 3, 6 and 10% in composites. Tensile strength and elongation were used to evaluate the mechanical properties of the films. While for water barrier properties was investigated by vapor transmission rate. The microstructure of the films was evaluated by using FT-IR, and SEM. The results showed that increasing the concentration of nanocellulose decreasing the tensile strength and elongation of composites. The concentration of 1% nanocellulose increased the WVTR and in greater amount will reduce the value of WVTR. Addition of nanocellulose decreased the transparency of the composite films. For further application, it can be used as a label for freshness label of smart packaging with the addition of functional material.
Optimization Ratio of Mixed Metal Soaps (Al-Ca) and Palm Fatty Acid Distillate (PFAD) on Making Grease
Authors: Sukmawati  , Lestari P P 
Published: January 2020

Abstract
Palm Fatty Acid Destilate (PFAD) to be used as a raw material for making oleochemical products, solid lubricant. This is caused by the composition of fatty acids contained in PFAD not much different from the composition of fatty acids found in palm oil. This study aims to determine the formulation of solid lubricants (grease) from PFAD and compound metal soap (Al-Ca) as thickener which has characteristics close to SNI solid lubricants and know the quality of solid lubricants produced. The method used in the manufacture of solid grease (grease) consists of two stages. The first stage is the process of making mixed metal soap (Al-Ca) by mixing PFAD and Al(OH)3-Ca(OH)2 and analyzing the mixed metal soap. The second stage is the manufacture of solid lubricants (grease) from mixed metal soap (Al-Ca) and PFAD as well as analyzing the resulting product.
Based on the research that has been done, the optimum solid lubricant obtained according to SNI standards is in the composition of A:B1, A1 is the ratio of Al(OH)3:Ca(OH)2 = 90%:10% and B1 is the ratio of metal soap:PFAD = 90 %:10%, so the density is 0.95gr/ml and the penetration value is 194 (25 °C).
Effect of Temperature on Electrodeposited Nickel Nitride Composite Coatings
Authors: Budi Esmar , Kusumawati Leli , Assita Wahyu Andiani , Indrasari Widyaningrum , Sugihartono Iwan , Teguh Budi Prayitno 
Published: January 2020

Abstract
In the present study, the effect of temperature during electrodeposition of Ni-TiN/Si3N4 composite coatings have been studied. The electrodeposition process was carried out for 15 minutes with a current density of 2.5 mA/cm2. A potensiostat system completed by an electrochemical cell with three electrodes was used for the experiment. Pt wire as the counter electrode, AgCl as the reference electrode and tungsten carbide (WC) as the working electrode. The electrolyte solution used consisted of 0,17 M NiCl2.6H2O, 0,38 M Ni2SO4.6H2O, 6 g/L TiN, 6 g/L AlN, 0,6 g/L Si3N4, 40 g/L H3BO3 and 0,6 g/L Sodium Dodecyl Sulfate (SDS). In this stydy, the temperature variations used were 35°C, 40°C and 45°C. The samples were characterized by using SEM, EDS, XRD and hardness test. The results show that the high electrodeposition temperature produce the smoother morphology and Ni grain refinement and lead to the increase in coating hardness.
The effect of Vanadium Addition on the Characteristics of LaCrO3 nanomaterial
Authors: Situmeang Rudy , Purniasari Lia , Oktavian Harist , Azmi Elsina , Sembiring Simon 
Published: January 2020

Abstract
Lanthanum chromite is a material that plays a large role in the development of fuel cells, catalysts, electronic devices, semiconductors, and magnetics. The application of this compound is determined by the material characteristics. The LaCr1-xVxO3 (where x = 0.01 – 0.03) compound was prepared using a simultaneous method of sol-gel and freeze-drying from salts of chrome, lanthanum, and vanadium in pectin solution. The characterization results using X-ray diffraction, diffuse-reflectance UV-Vis spectrophotometer, and SEM-EDS. X-ray Diffraction analysis showed that the materials formed have the main structure of ABO3 perovskite (such as LaCrO3 and LaVO3) with minor phases of LaVO4 while the band-gap energy of materials due to the addition of vanadium in LaCrO3, it shifts its energy to a lower direction, namely: 2.7; 2.4; 2.6 eV for LaCr1-xVxO3 (where x = 0, 0.01, 0.02, and 0.03) and SEM-EDS micrographs show that the distribution of the crystalline phase is fairly homogeneous, porous and nanorods.