The Processing of the Profile Surface of the Work-Pieces, Characterized by Low Rigidity

2020 ◽  
Vol 299 ◽  
pp. 852-860
Author(s):  
Anatoly A. Fomin ◽  
Vladimir G. Gusev ◽  
Nail F. Timerbaev
Keyword(s):  
Mechanical Characteristics ◽  
Flexural Rigidity ◽  
Geometric Error ◽  
Technological System ◽  
Design Parameters ◽  
Work Piece ◽  
Machined Surface ◽  
Spindle Unit ◽  
Physical And Mechanical Characteristics

This work indicates that the prediction of the geometric indicators of the quality of the machined surface in the design of technological operations for milling a profile surface of work-pieces with low rigidity is possible, on the basis of an analysis of the elastic displacements of the technological system elements, the flexural rigidity of the work-piece as a function of its initial dimensions, the locating chart and the physical and mechanical characteristics of the material being processed. The article describes the characteristics of the elements of the technological system for the profile milling of work-pieces of low rigidity; The analytical dependencies linking the elastic displacements of the work-piece during the processing of various wood species with elements of the milling mode and the design parameters of the mill are given. Extreme total elastic displacements of the technological system during the cutting process are determined. Mathematical models of the maximum geometric error of the machined surface, as a function of the work-piece's flexural rigidity and the spindle unit, are established. Based on the results of the analysis, recommendations for improving the accuracy of the product were developed.

On the influence of the shaped charge liner manufacture technology on the high-speed element characteristics

2020 ◽  
Author(s):  
V.I. Kolpakov ◽  
N.A. Kudyukov
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Shaped Charge ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Liner Material ◽  
Metal Spinning ◽  
Cold Stamping ◽  
Physical And Mechanical Characteristics

The paper introduces the results of numerical simulation of the functioning of shaped charges, whose liners are made of different materials. As a result of their functioning, these charges form high-speed elements. Typically, liners for such charges are produced by the cold stamping technology. An alternative method for producing the liners is metal spinning. Moreover, a spin formed liner is expected to have higher physical and mechanical properties compared to a stamped liner made of the same material and having the same geometrical parameters. To reveal the patterns of molding high-speed elements from stamped and spin formed liners, the action of shaped charges comprised of steel or copper segmental liners of small bending, was simulated numerically using the apparatus of continuum mechanics. The influence of the liner manufacture method was taken into account by varying the values of the physical and mechanical characteristics of the liner material. The design parameters of the simulated charge, with the exception of the liner bending, during the calculation study remained unchanged and corresponded to the parameters of the currently used samples. Following the numerical experiments results, the study shows that the elements molded from spin formed liners are less likely to become fractured while being formed and are also more integral (continuous) in comparison to the elements molded from stamped shaped charge liners.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

scholarly journals The Effect of Twisted Polymer Fiber on Physical and Mechanical Characteristics of Concrete C35

2018 ◽  
Vol 14 (1) ◽  
pp. 126-135
Author(s):  
Reza Mirzaei ◽  
Naser Zarifmoghaddam
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Modulus Of Elasticity ◽  
Mechanical Characteristics ◽  
Fiber Reinforced Concrete ◽  
Polymer Fiber ◽  
New Materials ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

 Concrete as the most used material, is known as an integral part of construction. So far, many studies have been done in the field of improving the quality of concrete that most of them have examined change in concrete mix which is called concrete mix plan. However, the use of additives and also replacing commonly used materials in concrete with new materials always has been noteworthy. In this study, description of tests that have been done on fiber reinforced concrete will be discussed. Also, the condition of concrete mix plan will be discussed. Comparison between results of the tests showed that Forta reinforced concretes have more compressive, flexural and tensile strength and modulus of elasticity than normal and ordinary concretes.Journal of the Institute of Engineering, 2018, 14(1): 126-135 

Determination of Turning Knife Thermal Stress during Longitudinal Turning

2016 ◽  
Vol 821 ◽  
pp. 649-654
Author(s):  
Marek Stránský ◽  
Jaroslav Horský
Keyword(s):  
Machine Tools ◽  
Inverse Relationship ◽  
Work Piece ◽  
Machined Surface ◽  
One Dimensional ◽  
Friction Heat ◽  
Longitudinal Turning ◽  
New Machine

A turning knife contacts a work piece during turning. Due to friction, heat is produced proportionally to the turning speed. The resulting temperature influences the quality of the machined surface and wear of the knife. Thus, new machine tools must be developed that minimize the production of unwanted heat. To accomplish this task, a new experimental knife was prepared with thermocouples both built into it and welded to its surface. The measurement process was supplemented by thermovision. Heat flux and surface temperatures were computed from subsurface data using a one-dimensional inverse relationship. The detailed temperature distribution on the surface of the turning knife was determined using a combination of these methods.

To Identify Key Geometric Errors of 3-Axis NC Machine Tool by Machining Accuracy Failure Mode Analysis

2019 ◽  
Author(s):  
Baobao Qi ◽  
Qiang Cheng ◽  
Zhifeng Liu ◽  
Dongyang Sun
Keyword(s):  
Machine Tool ◽  
Failure Mode ◽  
Failure Modes ◽  
Geometric Error ◽  
Mode Analysis ◽  
Major Influence ◽  
Work Piece ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Machined Surface

Abstract Machine tools usually cut two or more surfaces after the work piece clamped on work table. In order to improve the machining accuracy and optimize accuracy design, it is hoped that the geometric errors that influence the accuracy of machined surface prominently can be known beforehand, so the adjustment will be carried out with a definite objective rather than without any clue. Because the machining accuracy of each direction in 3-D space is different value, in this paper, machining accuracy failure mode was defined as the various combination of the machining accuracy of each direction according to whether it is up to the reserved objective value or not. A three-axis machine tool was selected as an example and there were 7 machining accuracy failure modes for it. Based on the generalized correlation analysis, the correlation relationships between 7 machining accuracy failure modes were analyzed, and the main failure modes that affect the machining accuracy of work piece to be machined were identified. For each machining accuracy failure mode, key geometric error that had major influence on it was identified based on sensitivity analysis. Finally, four stepped work pieces were milled by a 3-axis machine tool to illustrate the analytical method proposed in this study.

CONTROL OF CUTTING MODE PARAMETERS AND TOOL MATERIAL TO ENSURE THE VALUES OF ROUGHNESS PARAMETERS WHEN TURNING STEELS 09H17N7YU, 12H18N10T AND 13H15N5 AM-3

2021 ◽  
pp. 32-37
Author(s):  
B. Ya. Mokritskii
Keyword(s):  
Stainless Steels ◽  
Mechanical Characteristics ◽  
Cutting Tool ◽  
Tool Material ◽  
Roughness Parameters ◽  
Surface Processing ◽  
Corrosion Resistant ◽  
And Performance ◽  
Physical And Mechanical Characteristics

When processing hard-to-process stainless steels, it is difficult to maintain a compromise between the quality of the treated surface, processing performance and the period of operation of the cutting tool to the permissible value of its wear. The more specialized the physical and mechanical characteristics and performance properties of such steel, the more difficult it is to reach a compromise. The paper shows the results of controlling the parameters of the cutting mode to ensure the required roughness parameters when turning highly corrosion-resistant stainless steels 09H17N7YU, 12H18N10T and 13H15N5 AM-3.

Optimization of the processes of introducing nanosilver into the structure of chipboard as an absorbent of formaldehyde

2020 ◽  
Author(s):  
A.M. Yabbarova ◽  
◽  
E.I. Stenina ◽  
Keyword(s):  
Systematic Approach ◽  
Mechanical Characteristics ◽  
Colloidal Solution ◽  
Layer By Layer ◽  
Nanosized Particles ◽  
Particle Board ◽  
Colloidal Solutions ◽  
Properties Of Materials ◽  
Physical And Mechanical Characteristics

A promising direction in producing the special-purpose plates is to increase their physical and mechanical characteristics, reduce toxicity, and use highperformance equipment. The article analyzes the results of experiments to determine the physicomechanical parameters of particle board. Using a colloidal solution of nanosilver, the optimal models of layer-by-layer introduction of nanosilver into the structure of particle board (as a formaldehyde absorber) are determined. The use of colloidal solutions of nanosized particles of various metals significantly improves a number of operational and technological properties of materials that would raise the quality of life of people to a new health-saving level. The article is an overview based on the principles of a systematic approach to using the sound methods and techniques of scientific research and contevporary means of scientific investigation.

Obtaining low-energy cement from industrial raw material

2020 ◽  
pp. 34-40
Author(s):  
N. N. Zhanikulov ◽  
B. T. Taymasov ◽  
I. N. Borisov ◽  
M. S. Dauletiyarov ◽  
M. Zh. Aitureev ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Raw Materials ◽  
Low Energy ◽  
Raw Material ◽  
Pyrite Cinder ◽  
Clay Component ◽  
Free Cao ◽  
Technogenic Raw Materials ◽  
Physical And Mechanical Characteristics

The results of obtaining Portland cement by lowenergy technology using technogenic raw materials are presented. Coal wastes and tephritobasalt in a ratio of 1: 1 were used as the clay component, instead of scarce pyrite cinder, granular lead slags were used. The regularities of the influence of the compositions of the blends, saturation coefficient, silicate and alumina modules, firing modes on the chemical and mineral composition and quality of clinker and cement are established. The composition of the raw mixes was calculated according to the ROCS program, the content of free CaO in the clinker was determined. The strength of experimental cement was tested after 7 and 28 days of hardening. Its physical and mechanical characteristics and structure were studied.

scholarly journals Dynamic model of closure the liner

2020 ◽  
pp. 114-122
Author(s):  
I. V. Dmytriv I. V.
Keyword(s):  
Cylindrical Shell ◽  
Modulus Of Elasticity ◽  
Mechanical Characteristics ◽  
Vacuum Pressure ◽  
Design Parameters ◽  
Radial Deformation ◽  
Central Angle ◽  
Radial Plane ◽  
Working Length ◽  
Physical And Mechanical Characteristics

Annotation Purpose. Develop analytical dependences for modeling the speed and dynamics of deformation of liner depending on its design parameters and physical and mechanical characteristics, taking into account the technological parameters of the process. Methods. Based on the system of geometric equilibrium equations for a cylindrical shell, taking into account the isotropy of the medium and the momentless stress state, the spatial action of forces and pre-tension of the liner, developed analytical equations that allow modeling the dynamics of deformation of liner in time, which allows to determine the time constant of the system “liner – milking cup”. Results. Analytical dependences of the dynamics of deformation of liner in time in the radial plane and the rate of deformation depending on its design parameters and physical and mechanical characteristics of the material are developed. Parameters for deformation simulation are: R – radius of liner, Е – modulus of elasticity, ρ – the density of the rubber material, h – thickness of liner, рн – vacuum pressure, l – the length of the active part of liner, ν – Poisson's coefficient for rubber, Fн – force of tension of liner. Depending on the central angle in the radial plane of the section, the shape of the deformation of the liner is modeled along its entire working length during the closing and opening stroke. Conclusions. The obtained dependences allow to model the dynamics of deformation of liner in the radial plane depending on its design parameters and physical and mechanical characteristics of the material. The developed analytical dependences take into account the pre-tension of the liner, vacuum pressure and allows modeling depending on the central angle in the radial plane of the rubber section. The use of the developed analytical dependences makes it possible to substantiate the main parameters that affect the process of closing and opening of the liner. The characteristic of the deformation in the cross section of the largest deformation is that the tension of the liner does not affect the deformation characteristic. This is due to the isotropy property of the cylindrical shell and the elastic isotropic properties. Keywords: liner, vacuum pressure, modulus of elasticity, radial deformation, coordinate system, tension of rubber, the cylindrical shell, the isotropic medium.

Evaluation of Concrete Produced with Pebble from the Region of Tangará da Serra-MT

2014 ◽  
Vol 600 ◽  
pp. 264-270
Author(s):  
Karita P. Carvalho ◽  
Albéria C. Albuquerque ◽  
Juzélia S. Costa
Keyword(s):  
Mechanical Characteristics ◽  
Low Cost ◽  
Particle Packing ◽  
Mechanical Resistance ◽  
Hardened Concrete ◽  
Structural Concrete ◽  
Manufacturing Costs ◽  
Physical And Mechanical Characteristics

The distance of the points of delivery of aggregates stimulate entrepreneurs to search for new alternatives that meet their needs, with low cost and quality. This study rescues the use of pebble on the concrete in the region of Tangará da Serra - MT. Willing to collaborate with the industry, a concrete was produced using methods of particle packing in order to provide to the manufacturer a proposal that makes possible the quality of the product supplied. The aggregate and the cement were tested according to their physical and mechanical characteristics, while the properties of the hardened concrete were evaluated according to their mechanical resistance. The results indicated that the mix with pebble aggregate have suitable properties to be used as a structural concrete. Earnings due to rationalization, quality and reducing manufacturing costs are factors that will contribute to the product acceptance in the market.

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