Computer Simulation of the Combined Process "Helical Rolling-Pressing"

2016 ◽  
Vol 716 ◽  
pp. 614-619 ◽  
Author(s):  
Abdrakhman Naizabekov ◽  
Sergey Lezhnev ◽  
Alexandr Arbuz ◽  
Evgeniy Panin
Keyword(s):  
Computer Simulation ◽  
Deformation Zone ◽  
Software Package ◽  
Innovation Process ◽  
Helical Rolling ◽  
Combined Process ◽  
Friction Coefficients ◽  
The Matrix ◽  
Optimal Values

In this work a simulation of the innovation process "helical rolling – pressing" in the software package Simufact.Formingwas performed. The result is several models of this process. To analyze the feasibility of the process various key parameters that have a significant impact on the implementation processwere carried out. As a result, the optimal values of friction coefficients in the rolls and in the matrix, the angle of intersection of channels in the matrix and the distance of matrix from the deformation zone of the rollswere obtained.

scholarly journals Simulation of the combined process “helical rolling-pressing” in the software package Simufact. Forming

2016 ◽  
Vol 80 ◽  
pp. 02006 ◽  
Author(s):  
Naizabekov Abdrakhman ◽  
Lezhnev Sergey ◽  
Panin Evgeniy ◽  
Arbuz Alexandr
Keyword(s):  
Software Package ◽  
Helical Rolling ◽  
Combined Process

scholarly journals D-Optimal Slope Design for Second Degree Kronecker Model Mixture Experiment With Three Ingredients

2020 ◽  
Vol 9 (2) ◽  
pp. 30
Author(s):  
Ngigi Peter Kung’u ◽  
J. K. Arap Koske ◽  
Josphat K. Kinyanjui
Keyword(s):  
Information Matrix ◽  
Coefficient Matrix ◽  
Three Dimensions ◽  
Matrix Means ◽  
The Matrix ◽  
Optimal Values ◽  
The Moment ◽  
Product Algebra ◽  
Slope Design ◽  
Second Degree

This study presents an investigation of an optimal slope design in the second degree Kronecker model for mixture experiments in three dimensions. The study is restricted to weighted centroid designs, with the second degree Kronecker model. A well-defined coefficient matrix is used to select a maximal parameter subsystem for the model since its full parameter space is inestimable. The information matrix of the design is obtained using a linear function of the moment matrices for the centroids and directly linked to the slope matrix. The discussion is based on Kronecker product algebra which clearly reflects the symmetries of the simplex experimental region. Eventually the matrix means are used in determining optimal values of the efficient developed design.

The Influence of RuO2 Addition on the Thermoelectric Properties of BiSbTe Alloys

2012 ◽  
Vol 512-515 ◽  
pp. 1651-1654 ◽  
Author(s):  
Yu Kun Xiao ◽  
Zhi Xiang Li ◽  
Jun Jiang ◽  
Sheng Hui Yang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Combined Process ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Factor Α ◽  
P Type

P-type BiSbTe/RuO2 composite was fabricated using a combined process of melting and spark plasma sintering. The XRD patterns showed that RuO2 reacted with the matrix for the RuO2 content of 1.0 wt% and 4.0 wt% samples. The measured thermoelectric properties showed that the highest electrical conductivity was obtained for the sample with 2.0 wt% RuO2. The power factor (α2σ/κ) decreased with the increase of RuO2 below 450 K. The lattice thermal conductivity was lower than that of BiSbTe over the whole temperature range for BiSbTe/2.0 wt% RuO2.

Scanning Electron Microscopy of Rubber Tear

1977 ◽  
Vol 50 (5) ◽  
pp. 875-883 ◽  
Author(s):  
W. D. Bascom
Keyword(s):  
Deformation Zone ◽  
Aging Process ◽  
Simple Technique ◽  
Chain Scission ◽  
Surface Forces ◽  
The Other ◽  
Qualitative Information ◽  
Carbon Filler ◽  
The Matrix ◽  
Initial Appearance

Abstract A relatively simple technique has been described which allows observation of the deformation zone at tear tips in rubber specimens. Investigation of various rubbers revealed qualitative information about the type of yielding that occurs in the deformation zone under different conditions. The initial appearance of the tear tip in nitrile, polybutadiene (both with and without carbon filler), and natural rubber suggests a process of stretching followed by rupture and then relaxation onto the tear walls. Only in the case of a fluoro-elastomer was there evidence of cavitation, although microcavitation (of sizes ≪1 µm) may be occurring in the other rubbers at much higher magnification. On the other hand, aging in laboratory air had the dramatic effect of producing fibrous and nodular networks in the tear tip material of all the rubbers except the fluoroelastomer. In the first few hours, the network structure developed as cavities (Figure 9), but after 24 h the network was fully developed across the tear. The aging process is very likely an ozone attack not only on the rubber under stress at the tear tip, but also on the rubber on the tear wall. It is quite possible that there were residual stresses in the material on the wall which facilitated attack. Chain scission appeared to be allowing the rubber to relax by viscous flow under the action of surface forces. These results point up the need to distinguish between failure controlled by pure stress and failure assisted by oxidation/ozonolysis in studies of slow tear growth in rubbers. The SEM technique also provides information about fillers. Their elemental composition can be determined by XES, and some qualitative information can be gained about their adhesion to the matrix and their effect on tear tip yielding.

Maximizing the Performance of Cased Munitions Under Realistic Constraints

2010 ◽  
Author(s):  
Kenneth C. Walls ◽  
David L. Littlefield ◽  
David E. Lambert
Keyword(s):  
Titanium Alloy ◽  
Software Package ◽  
Test Problem ◽  
Energetic Material ◽  
Design Parameters ◽  
Design Constraints ◽  
Optimization Software ◽  
Optimal Values ◽  
Explosive Detonation ◽  
Case Design

In order to make the process of fragmentation of warhead cases more systematic, we have developed a procedure that makes use of nonlinear optimization to derive optimal values for case design parameters subject to various design constraints. A framework has been developed that makes use of the optimization software package LS-OPT driving the hydrocode CTH (CTH is developed and maintained at Sandia National Laboratories, LS-OPT is commercially available from Livermore Software Technology Corp.). CTH was used to model the explosive detonation and determine the resultant kinetic energy delivered to the case by the energetic material. As an example of application of the framework, a test problem was run using a case configuration consisting alternating titanium alloy and polymer layers.

scholarly journals Simulation of Ingotless Rolling-Extruding of Rods from Alloy of Al-Zr System and Investigating into their Properties

2020 ◽  
Vol 837 ◽  
pp. 3-8
Author(s):  
Vadim Bespalov ◽  
Sergey Sidelnikov ◽  
Ruslan Sokolov ◽  
Alexander Chumak ◽  
Denis Voroshilov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Computer Simulation ◽  
Software Package ◽  
Processing Parameters ◽  
Process Conditions ◽  
Laboratory Unit ◽  
Deformation Parameters ◽  
3D Software ◽  
Deform 3D

Computer simulation of the process of ingotless rolling-extruding (IRE) of aluminum alloy rods with a content of 0.15% zirconium in the Deform 3D software package performed. The temperature, speed and deformation parameters of the treatment of the investigated alloy determined under different process conditions. To check the adequacy of the models, rod samples were made on a CRE-200 laboratory unit at specified processing parameters. Using the Deform 3D software package, the forces acting on the rolls and the extruding die during the IRE determined and their comparison with tensometric experimental data presented. The mechanical properties, electrical resistivity of semi-finished products after processing by the method of ingotless rolling-extruding and for conditions of their heating to 230 °C investigated. Technological recommendations for the manufacture of deformed semi-finished products using the method of ingotless rolling-extruding are proposed.

Study of the Tubular Billets Geometric Characteristics during Computer Simulation of the Rotary Piercing Process

2019 ◽  
Vol 946 ◽  
pp. 788-793
Author(s):  
Vladimir A. Toporov ◽  
Aleksandr Bogatov ◽  
Danis Nukhov
Keyword(s):  
Computer Simulation ◽  
Contact Surface ◽  
Research Methodology ◽  
Deformation Zone ◽  
Rotation Frequency ◽  
Step Length ◽  
Geometric Characteristics ◽  
Feed Angle ◽  
Tubular Billet ◽  
Surface Length

The results of the computer simulation of the tubular billet rotary piercing process are presented. The research methodology of the deformation zone geometric ratios with due regard for the tubular billet change of shape at each helical curve step was developed .The changes pattern of the helical curve step length (li), quotient reduction (Δr/r0), ratio of the tubular billet radius to the contact surface width (r/b), contact surface length of the tubular billet (l0) with a roll, depending on the feed angle (β), roll rotation frequency (N) and plug nose extension at the gorge (Сg) was established.

On Determining Conditions for Optimal Performance of Cased Munitions

2011 ◽  
Author(s):  
Kenneth C. Walls ◽  
David L. Littlefield ◽  
David E. Lambert
Keyword(s):  
Software Package ◽  
Energetic Material ◽  
Design Parameters ◽  
Design Constraints ◽  
Optimization Software ◽  
Optimization Study ◽  
Optimal Values ◽  
Free Parameters ◽  
Explosive Detonation ◽  
Case Design

In order to make the process of fragmentation of warhead cases more systematic, we have developed a procedure that makes use of nonlinear optimization to derive optimal values for case design parameters subject to various design constraints. A framework has been developed that makes use of the optimization software package LS-OPT driving the hydrocode CTH (CTH is developed and maintained at Sandia National Laboratories, LS-OPT is commercially available from Livermore Software Technology Corp.). CTH was used to model the explosive detonation and determine the resultant kinetic energy delivered to the case by the energetic material. In this follow-on effort to a previous study [1], the range of constraints and free parameters used in the optimization study was expanded.

scholarly journals Lime based Dry Mixes with Carbonate Aggregates

2019 ◽  
Vol 8 (11) ◽  
pp. 3289-3292 ◽  
Keyword(s):  
Mechanical Properties ◽  
Quartz Sand ◽  
Carbonate Rocks ◽  
Physical And Mechanical Properties ◽  
Lime Mortar ◽  
Fine Aggregates ◽  
Lime Mortars ◽  
The Matrix ◽  
Optimal Values ◽  
Quarry Dust

The use of carbonate rocks as aggregates for cement concretes and mortars is limited due to their insufficient strength and the threat of corrosion. The use of quarry dust from crushing carbonate rocks are technically and economically feasible in building compositions based on air-hardening lime. The results of the study of the effect of replacing a part of quartz sand in lime mortar by limestone and dolomite fine aggregates on the basic physical and mechanical properties of lime mortars for restoration are presented in the paper. The matrix of planning experiments, which allows increasing the informativity of the research results in order to reduce the number of experiments in the search for optimal values, is proposed. The efficiency of replacement of the quartz sand with quarry dust of carbonate rocks in the production of dry mixes for restoration is shown.

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