scholarly journals Design, Simulation and Optimization of an Additive Laser-Based Manufacturing Process for Gearbox Housing with Reduced Weight Made from AlSi10Mg Alloy

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 67
Author(s):  
Liubov Magerramova ◽  
Vladimir Isakov ◽  
Liana Shcherbinina ◽  
Suren Gukasyan ◽  
Mikhail Petrov ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Strength Properties ◽  
Body Parts ◽  
The Finite Element Method ◽  
Technological Parameters ◽  
Simulation And Optimization ◽  
Precision Casting ◽  
Production Techniques ◽  
Material Forming ◽  
Physical And Mechanical Characteristics

The gas turbine engine's (GTE) development aims for the increasing the efficiency, strength, reliability and safety of its components. To create competitive engines, housing parts and components with high functionality and reduced weight are needed. Especially difficult in the design and production are the gearboxes for aviation GTE. Traditional technologies based on precision casting or material forming operations have significant limitations due to the complexity of fulfilling multiple different requirements. Nowadays, one of the progressive production techniques is additive manufacturing. The article presents the results of computational and experimental studies that substantiate the applicability of laser additive technology to reduce the mass of body parts by up to 15% while ensuring their strength properties. The physical and mechanical characteristics of aluminum alloys acceptable for the manufacturing of housing parts were analyzed. The necessary characteristics of the powder alloy of the Al-Si system and the technological parameters of the L-PBF of the modified housing of the gear reducer are established. Using the finite element method (FEM) the L-PBF process was numerically simulated and the technological modes for synthesis of the AlSi10Mg alloy powder were optimized. With the help of a serial 3D printer ProX320DMP, the prototype of a gear housing was manufactured.

scholarly journals RESEARCH OF PHYSICAL AND MECHANICAL PROPERTIES OF WOOD-FIBER MATERIALS

2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Strength Properties ◽  
Grinding Process ◽  
Technological Parameters ◽  
Fiber Materials ◽  
Traditional Construction

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.

scholarly journals Управление физико-механическими характеристиками бетона за счет варьирования высоты и шага технологических выступов хомутов виброцентрифугирующих устройств

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Cross Section ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Technological Parameters ◽  
Axial Tensile ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

Для регулирования вариатропной структуры центрифугированных изделий авторы данной статьи совместили процесс центрифугирования с вибрированием. Во время эксперимента вибрации формы обеспечивались за счет надетых на валы установки хомутов. Представлена авторская экспериментальная установка для создания виброцентрифугированных образцов кольцевого сечения с вариатропной структурой, а также способ их изготовления. Выделены технологические параметры вибрирования, которые оказывали наиболее значимое влияние на характеристики виброцентрифугированного бетона, конструкций и изделий из него. В опытах варьировались высота технологических выступов хомутов и шаг между ними. Исследовалось влияние этих факторов на физико-механические характеристики бетона: плотность; кубиковая прочность на сжатие; призменная прочность на сжатие; прочность на растяжение при изгибе; прочность на осевое растяжение. Приведен анализ результатов экспериментальных исследований и получены следующие физико-механические характеристики виброцентрифугированных бетонов, изготовленных с использованием хомутов: лучшие – с высотой технологических выступов 5 мм и шагом между ними 30 мм, самый низкий показатель – соответственно 2,5 мм при любом шаге. Ключевые слова: виброцентрифугированный бетон, физико-механические характеристики, прочность при сжатии, плотность, бетонная смесь, центрифугирование, прочность при изгибе To regulate the variatropic structure of centrifuged products, the authors of this article combined the process of centrifugation with vibration. During the experiment, vibrations of the mold were provided with clamps set on the shafts of the installation. The author's experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure, as well as a method for their manufacture is presented. The technological parameters of vibration, which had the most significant effect on the characteristics of vibrocentrifuged concrete, structures and products made of it, were identified. In the experiments, the height of the technological protrusions of the clamps and the pitch between them were varied. The influence of these factors on the physical and mechanical characteristics of concrete was investigated: density; cube compressive strength; prismatic compressive strength; bending tensile strength; axial tensile strength. Analysis of the results of experimental studies is given and the following physical and mechanical characteristics of vibrocentrifuged concretes made using clamps have been obtained: the best ones with a height of technological protrusions of 5 mm and a step between them of 30 mm, the lowest indicator is, respectively, 2.5 mm at any step. Keywords: vibrocentrifuged concrete, physical and mechanical characteristics, compressive strength, density, concrete mix, centrifugation, flexural strength

Numerical Modeling of Thermobonded Nonwovens

2004 ◽  
Vol os-13 (1) ◽  
pp. 1558925004os-13 ◽  
Author(s):  
Dieter H. Mueller ◽  
Markus Kochmann
Keyword(s):  
Experimental Data ◽  
Nonlinear Behavior ◽  
Fiber Material ◽  
Tensile Behavior ◽  
Fiber Bundles ◽  
The Finite Element Method ◽  
Technological Parameters ◽  
Numerical Effort ◽  
Production Techniques ◽  
Temperature And Pressure

In thermobonded nonwovens, the design of the bond point geometry is of major importance to the desired mechanical behavior. Despite the geometry's significance the selection is subject to a trial and error approach. This paper describes a numerical method for the prediction of the nonwovens tensile behavior depending on the bond point geometry and process parameters. The tensile behavior of thermobonded nonwovens is modeled in a numerical model using the Finite Element Method (FEM). The approach covers the influence of the shape and size of the bonded area as well as the properties of the non-woven. The influence of the technological parameters during the bonding process such as process temperature and pressure, are also covered. The solidified area within the bond point is represented using solid elements. The connection between the bonded areas is modeled using link elements, representing the connecting fibers. This approach covers the nonlinear behavior caused by the fiber material properties and geometry. Sets of fibers are combined into fiber bundles in order to reduce the numerical effort. The fiber orientation within the nonwoven is taken into account in order to represent the different fiber distributions caused by the nonwovens production techniques. The mechanical properties of fibers and fiber bundles are taken from experimental data and are mapped onto the model. The model is verified using experimental data from tensile testing.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

FEMLIB: An Object-Oriented Framework for Optimization and Simulation

1995 ◽  
Author(s):  
Michael M. Tiller ◽  
Jonathan A. Dantzig
Keyword(s):  
Material Properties ◽  
Object Oriented ◽  
The Finite Element Method ◽  
Simulation And Optimization ◽  
Gradient Based ◽  
Level Problem ◽  
Simulation Results ◽  
Optimization And Simulation ◽  
High Level ◽  
Simulation Parameters

Abstract In this paper we discuss the design of an object-oriented framework for simulation and optimization. Although oriented around high-level problem solving, the framework defines several classes of problems and includes concrete implementations of common algorithms for solving these problems. Simulations are run by combining these algorithms, as needed, for a particular problem. Included in this framework is the capability to compute the sensitivity of simulation results to the different simulation parameters (e.g. material properties, boundary conditions, etc). This sensitivity information is valuable in performing optimization because it allows the use of gradient-based optimization algorithms. Also included in the system are many useful abstractions and implementations related to the finite element method.

scholarly journals Effects of Concrete Core Technological Defects on the Strength of Tube Confined Concrete Elements

2018 ◽  
Vol 7 (3.2) ◽  
pp. 376
Author(s):  
Oleksandr Semko ◽  
Olga Gukasian ◽  
Serhii Skliarenko
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Fracture Pattern ◽  
Confined Concrete ◽  
Concrete Core ◽  
Different Types ◽  
Technological Defects ◽  
Concrete Elements ◽  
Core Production ◽  
Physical And Mechanical Characteristics

The paper sums up a series of experimental studies describing the influence of most types of concreting common defects, such as core weakening: weak compression inclusions, voids, height heterogeneity of concrete. The basis of the experimental study is the research on the concrete core production conditions influence on tube confined concrete elements and the change in physical and mechanical characteristics of the elements. The concrete strength is estimated based on the results of the study of specially shaped samples with given dimensions. According to the results of concreting samples with different types of modeled defects (abnormalities) inspection, the most dangerous damages of the concrete core were identified and different variants of the height strength retrogression of the elements under study were analyzed. As a result, the degree and type of damage to the tube confined concrete elements core of the samples, which affect the fracture pattern, was established. 

scholarly journals Investigations on Torsion of the Two-Chords Single Laced Members

2017 ◽  
Vol 25 (2) ◽  
pp. 147-160
Author(s):  
Paweł Lorkowski ◽  
Bronisław Gosowski
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
Second Moment ◽  
Steel Columns ◽  
Numerical Studies ◽  
Traction Network ◽  
Railway Traction ◽  
Parametric Analyses ◽  
The Relationship

Abstract The paper presents experimental and numerical studies to determine the equivalent second moment of area of the uniform torsion of the two-chord steel single laced members. The members are used as poles of railway traction network gates, and steel columns of framed buildings as well. The stiffness of uniform torsion of this kind of columns allows to the determine the critical loads of the spatial stability. The experimental studies have been realized on a single - span members with rotation arrested at their ends, loaded by a torque applied at the mid-span. The relationship between angle of rotation of the considered cross-section and the torque has been determined. Appropriate numerical model was created in the ABAQUS program, based on the finite element method. A very good compatibility has been observed between experimental and numerical studies. The equivalent second moment of area of the uniform torsion for analysed members has been determined by comparing the experimental and analytical results to those obtained from differential equation of non-uniform torsion, based on Vlasov’s theory. Additionally, the parametric analyses of similar members subjected to the uniform torsion, for the richer range of cross-sections have been carried out by the means of SOFiSTiK program. The purpose of the latter was determining parametrical formulas for calculation of the second moment of area of uniform torsion.

Formation of coagulated colloidal silica in high-temperature mineralizing fluids

2002 ◽  
Vol 66 (4) ◽  
pp. 547-553 ◽  
Author(s):  
B. J. Williamson ◽  
J. J. Wilkinson ◽  
P. F. Luckham ◽  
C. J. Stanley
Keyword(s):  
High Temperature ◽  
Hydrothermal Fluid ◽  
Colloidal Silica ◽  
Fluid Transport ◽  
Experimental Studies ◽  
Hydrothermal Fluids ◽  
Ore Formation ◽  
Colloidal Gel ◽  
Material Forming ◽  
Mineralizing Fluids

AbstractRecent experimental studies have suggested that colloidal silica can form in high-T (300 to >700°C) hydrothermal fluids (Wilkinson et al., 1996). Natural evidence in support of this was found by Williamson et al. (1997) who proposed a colloidal (gel) silica origin for <50 μm irregularly-shaped inclusions of quartz contained in greisen topaz from southwest England. Confocal and microprobe studies, presented here, strengthen this argument although rather than forming a gel in the hydrothermal fluid, it is suggested that the colloidal silica aggregated as a viscous coagulated colloid, with much of its volume (<10 to 30 vol.%) consisting of metal (mainly Fe) -rich particles. This is evident from the largely solid nature of metal-rich shrinkage bubbles contained at the margins of the inclusions of quartz which shows that the material forming the inclusions contained much less liquid than would be expected in a silica gel. These findings may have important implications for models of ore formation since the precipitation of a coagulated colloid could inhibit hydrothermal fluid transport and cause co-deposition of silica and entrained ore-forming elements. The mode of formation of the colloidal silica and further implications of the study are discussed.

scholarly journals RESEARCH OF THE OF BULK MATERIAL MOVEMENT PROCESS IN THE INACTIVE ZONE BETWEEN SCREW SECTIONS

2020 ◽  
Vol 60 (1) ◽  
pp. 261-268
Author(s):  
O.M. Trokhaniak ◽  
R.B. Hevko ◽  
O.L. Lyashuk ◽  
T.A. Dovbush ◽  
B.V. Pohrishchuk ◽  
...  
Keyword(s):  
Optimal Design ◽  
Bulk Material ◽  
Experimental Studies ◽  
Screw Conveyor ◽  
Technological Parameters ◽  
Movement Process ◽  
Curved Paths ◽  
Agricultural Materials

The article presents the results of theoretical and experimental studies of the process of moving bulk material in the inactive zone between hinged screw sections of a flexible screw conveyor. The influence of the gap between the edges of adjacent screw sections and the magnitude of their circular displacement on the process of continuous transportation of bulk material is presented. The results of theoretical and experimental studies are compared. This will allow choosing the optimal design, kinematic and technological parameters of the developed sectional screw working body when transporting bulk agricultural materials along curved paths, both in horizontal and inclined directions, as well as along curved paths.

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