scholarly journals Особенности разрушения ударников из пористого сплава на основе вольфрама с упрочняющим наполнителем при взаимодействии с бронепреградами

2020 ◽  
Vol 90 (3) ◽  
pp. 434
Author(s):  
А.Н. Ищенко ◽  
С.А. Афанасьева ◽  
Н.Н. Белов ◽  
В.В. Буркин ◽  
С.В. Галсанов ◽  
...  
Keyword(s):  
High Speed ◽  
Complex Structure ◽  
Experimental Studies ◽  
Effective Area ◽  
Depth Of Penetration ◽  
Iron Cobalt ◽  
Nickel Iron ◽  
High Speed Collision ◽  
Localization Of Plastic Deformation ◽  
Crater Morphology

In this work, computational and experimental studies of the process of destruction of composite firing pin of porous alloy tungsten+nickel+iron+cobalt with 10 % content of titanium tungsten carbide at high-speed collision with steel barriers. It is shown that at ballistic tests with the broad range of speeds, significant exceeding of penetration of these firing pins in steel barriers in comparison with a mass-dimensional analog of the W-Ni-Fe-90 alloy. Based on the analysis of the crater morphology and structure of the striker fragments after penetration into the barrier, the assumption of implementation of the self-sharpenings mode of the firing pin, by means of localization of plastic deformation is made that leads to decrease in the effective area of interaction and increase in depth of penetration. Modification of a mathematical model of a porous ideal elasto-plastic solid with complex structure for the description of destruction with a possibility of accounting of the adiabatic shift mechanism in the course of interaction of the firing pin and a barrier is carried out.

Impact Properties of Metal-Ceramic Alloys Based on Tungsten-Nickel-Iron-Cobalt System at High-Speed Interaction

2014 ◽  
Vol 1013 ◽  
pp. 176-181
Author(s):  
Svetlana Afanas'eva ◽  
Nikolai Belov ◽  
Yurii Biryukov ◽  
Vladimir Burkin ◽  
Aleksandr Ishchenko ◽  
...  
Keyword(s):  
High Speed ◽  
High Energy ◽  
Porous Composite ◽  
Ceramic Filler ◽  
Iron Cobalt ◽  
Nickel Iron ◽  
Experimental Part ◽  
Metal Ceramic ◽  
Laboratory Technology ◽  
The Given

In the given work, the investigations have been directed to the creation of porous composite materials with MgO and B4C ceramic filler. The laboratory technology of obtaining rods from the given materials has been developed. The experimental part of this work was carried out on ballistic set-ups with shaft-reactive and electrochemical technologies of throwing with the use of high-energy plastisol fuels with nanosize metallic fillers. Mathematical modeling of the behavior of materials under conditions of high-speed interaction was carried out in the framework of a porous elastoplastic medium according to different destruction mechanisms.

scholarly journals Model of high-speed shock interaction with compatible type

2020 ◽  
pp. 64-72
Author(s):  
Anatolii Kovtun ◽  
Volodymyr Tabunenko ◽  
Serhii Nesterenko
Keyword(s):  
Experimental Research ◽  
Military Personnel ◽  
High Speed ◽  
Low Cost ◽  
Experimental Studies ◽  
Shock Interaction ◽  
Military Operations ◽  
Depth Of Penetration ◽  
Hollow Cylinders ◽  
Protective Structures

In connection with military operations, the issue of developing protection for military personnel against bullets and splinters remains an issue. Modern studies of the interaction of bullets and fragments with protective obstacles are based on the search for new types of structures and materials of protection. The focus is on the development of NATO-compliant protective structures to increase the level of protection for military personnel using low-cost, affordable materials with minimal production and intended use. Despite some advances in the study of solid-body impact, the known results of theoretical and experimental studies do not describe the overall picture of the interaction of the element of damage and interference. When designing protective structures, only certain aspects of the shock interaction are considered, based on the absorption of the kinetic energy of the element of damage. Therefore, it remains important for the scientific and technical task - to continue the study of the process of interaction of bullets (fragments) with protective obstacles, at the stages of penetration, penetration and their departure, which will allow to develop new models of protection structure of military personnel that are relevant for military use. The main method of studying the process of striking and punching an obstacle with a bullet (fragment) is a combination of analytical and experimental studies. Analytical methods of research are based on mathematical modeling of stages of interaction of bullets (fragments) with elements of a protective obstacle with the subsequent carrying out of corresponding mathematical calculations. Experimental research methods are based on determining the level of security and require complex research in laboratory and polygonal conditions. The combination of analytical and experimental research results makes it possible to consider the level of security more fully. In this work the process of interaction of a ball (fragment) with the protective obstacles formed by a set of hollow cylinders of compatible type is considered. Models for determining the depth of penetration of the impactor into the obstacle in the form of a set of hollow cylinders of compatible type are proposed. The results of calculations of the depth of penetration of the ball from Kalashnikov (AK-74) in steel hollow cylinders of compatible type are presented. Further research is concerned with improving the design of armor by developing new technical solutions using the latest technologies.

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.

scholarly journals Diffraction Efficiency Characteristics for MEMS-Based Phase-Only Spatial Light Modulator with Nonlinear Phase Distribution

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 62
Author(s):  
Remington S. Ketchum ◽  
Pierre-Alexandre Blanche
Keyword(s):  
Diffraction Efficiency ◽  
High Speed ◽  
Phase Distribution ◽  
Complex Structure ◽  
Spatial Light Modulators ◽  
Light Modulator ◽  
Micro Electro Mechanical Systems ◽  
Light Modulators ◽  
Nonlinear Phase ◽  
Liquid Crystal On Silicon

Micro-electro mechanical systems (MEMS)-based phase-only spatial light modulators (PLMs) have the potential to overcome the limited speed of liquid crystal on silicon (LCoS) spatial light modulators (SLMs) and operate at speeds faster than 10 kHz. This expands the practicality of PLMs to several applications, including communications, sensing, and high-speed displays. The complex structure and fabrication requirements for large, 2D MEMS arrays with vertical actuation have kept MEMS-based PLMs out of the market in favor of LCoS SLMs. Recently, Texas Instruments has adapted its existing DMD technology for fabricating MEMS-based PLMs. Here, we characterize the diffraction efficiency for one of these PLMs and examine the effect of a nonlinear distribution of addressable phase states across a range of wavelengths and illumination angles.

scholarly journals Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3609
Author(s):  
Mykola Sysyn ◽  
Michal Przybylowicz ◽  
Olga Nabochenko ◽  
Lei Kou
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Dynamic Interaction ◽  
Theoretical Research ◽  
Rolling Stock ◽  
Monitoring Methods ◽  
Beam Dynamic ◽  
Track Geometry ◽  
Data Driven Approach ◽  
Support Conditions

The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.

Numerical and experimental studies on the thermal and static characteristics of multi-leaf foil thrust bearing

2021 ◽  
pp. 135065012110110
Author(s):  
Yu Guo ◽  
Yu Hou ◽  
Qi Zhao ◽  
Xionghao Ren ◽  
Shuangtao Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Failure Process ◽  
Experimental Studies ◽  
Elastic Model ◽  
Static Characteristics ◽  
Bearing Load ◽  
Foil Thrust Bearing ◽  
Cooling Air

Foil bearing is considered to be a promising supporting technology in high-speed centrifugal machinery. Due to the high-speed shearing effect in the viscous lubricant film, heat generation could not be ignored. In this paper, a thermo-elastic model of the multi-leaf foil thrust bearing is proposed to predict its thermal and static characteristics. In the model, modified Reynolds equation, energy equation, and Kirchhoff equation are solved in a coupling way. The contact area between the foil and welding plate is taken into account. Besides, the effect of cooling air on the bearing temperature is investigated. The ultimate load capacity and transient overload failure process of the bearing is analyzed and discussed. The effect of rotation speed on the bearing temperature is more obvious than that of the bearing load. The bearing temperature drops obviously by introducing the cooling air, and the cooling effect is improved with the supply pressure. The transient overload failure of the bearing occurs when the bearing load exceeds the ultimate value.

Interface Temperature Measurement and Experimental Studies of Super-High Speed Polishing of CVD Diamond Films

2010 ◽  
Vol 135 ◽  
pp. 271-276
Author(s):  
Shu Tao Huang ◽  
Li Zhou ◽  
Li Fu Xu
Keyword(s):  
Stainless Steel ◽  
Temperature Measurement ◽  
Temperature Rise ◽  
Diamond Film ◽  
High Speed ◽  
Experimental Studies ◽  
Pure Titanium ◽  
Cvd Diamond ◽  
Interface Temperature ◽  
Cvd Diamond Film

Super-high speed polishing of diamond film is a newly proposed method due to its outstanding features such as low cost and simple apparatus. The interface temperature rise is due to the friction force and the relative sliding velocity between the CVD diamond film and the polishing metal plate surface. In this paper, the interface temperature rise in super-high speed polishing of CVD diamond film was investigated by using the single-point temperature measurement method. Additionally, the influence of polishing plate material on the characteristics of super-high speed polishing has been studied. The results showed that cast iron is not suitable for super-high polishing, while both 0Cr18Ni9 stainless steel and pure titanium can be used for the super-high polishing of CVD diamond film. The quality and efficiency of polishing with 0Cr18Ni9 stainless steel plate is much higher than those of pure titanium, and the material removal rate could reach to 36-51 m/h when the polishing speed and pressure are 100 m/s and 0.17-0.31 MPa, respectively.

Characteristics of injection of diesel fuel, rapeseed oil and their mixtures in diesel engines of various types

2021 ◽  
pp. 167-178
Author(s):  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Rapeseed Oil ◽  
High Speed ◽  
Fuel Injection ◽  
Experimental Studies ◽  
Fuel Injector ◽  
High Speed Diesel ◽  
Engine Type

The necessity of adapting diesel engines to work on vegetable oils is justified. The possibility of using rapeseed oil and its mixtures with petroleum diesel fuel as motor fuels is considered. Experimental studies of fuel injection of small high-speed diesel engine type MD-6 (1 Ch 8,0/7,5)when using diesel oil and rapeseed oil and computational studies of auto-tractor diesel engine type D-245.12 (1 ChN 11/12,5), working on blends of petroleum diesel fuel and rapeseed oil. When switching autotractor diesel engine from diesel fuel to rapeseed oil in the full-fuel mode, the mass cycle fuel supply increased by 12 %, and in the small-size high-speed diesel engine – by about 27 %. From the point of view of the flow of the working process of these diesel engines, changes in other parameters of the fuel injection process are less significant. Keywords diesel engine; petroleum diesel fuel; vegetable oil; rapeseed oil; high pressure fuel pump; fuel injector; sprayer

Effect Of The Rib Inclination Angle On Liquid Film Spreading Over The Structured Surface

2015 ◽  
Vol 10 (1) ◽  
pp. 42-49
Author(s):  
Aleksandr Pavlenko ◽  
Oleg Volodin ◽  
Vladimir Serdyukov
Keyword(s):  
Liquid Film ◽  
Flow Rate ◽  
Inclination Angle ◽  
High Speed ◽  
Film Flow ◽  
Complex Geometry ◽  
Experimental Studies ◽  
Local Flow ◽  
Structured Packing ◽  
Film Spreading

Results of experimental studies on hydrodynamics of the film flow of liquid nitrogen over the surface of the single elements of structured packing are presented. The effect of inclination angle of the large ribs and perforation on the zones of liquid film spreading over the corrugated surface with microtexture at different Reynolds numbers of the film is shown based on a comparison of experimental data. It is shown that the angle of large rib inclination has a significant influence on redistribution of the local flow rate of liquid flowing on the surface with complex geometry. Analysis of results of the high-speed video revealed that in a vicinity of the vertical lateral edges of corrugated plates, the intense rivulet flows are formed, including those with separation from the film flow surface. This negative factor can lead to significant liquid accumulation and flow near the vertical edges of the structured packing and on the inner wall of the heat exchanging apparatuses and, finally, to a significant increase in the degree of maldistribution of local liquid flow rate over the crosssection, for instance, of the distillation columns.

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