scholarly journals Research on the influence of the clamping devices on the size of the perforated holes in long round pipes

2022 ◽  
Vol 960 (1) ◽  
pp. 012023
Author(s):  
D I Poiană ◽  
I Ionel ◽  
G Drăghici
Keyword(s):  
Plastic Deformation ◽  
Mechanical Characteristics ◽  
Optimal Shape ◽  
Cold Plastic Deformation ◽  
Deformation Processes ◽  
The Stability

Abstract When perforation by cold plastic deformation processes of long round pipes, the technological problems appear primarily at the deformation of the part section, in the perforation area by losing the stability of the part, in the case of holes made at a distance from the pipe ends. The purpose of the research was to determine the influence of the constructive shape of the pipe clamping devices in the perforation area, in order to determine the device that offers the best stability of the section, to allow obtaining possible holes as large in diameter. The research was based on the application of materials strength methods and the Castigliano method of solving the indeterminacy, related to the process of cold plastic deformation. The research materialized by determining some calculation relations and specific diagrams regarding the diameter’s variation of the perforated holes in the air environment, depending on the dimensions of the part and the mechanical characteristics of the part material, for different forms of clamping devices. The calculations were performed considering that the perforation is performed in air, with a punch applied from the outside of the considered piece. The calculation relations and the obtained diagrams allow the determination of the maximum orifices, for certain dimensions of the pipes and for different mechanical characteristics of the part material. At the conclusions, a comparison was made of the results obtained for the variants of clamping considered devices and the optimal shape of the device was established, which allows the making of the largest perforated holes in the part.

Determination of Constitutive Equation at the Deformation of Materials Using the Compression Test

2013 ◽  
Vol 837 ◽  
pp. 110-115 ◽  
Author(s):  
Monica Iordache ◽  
Eduard Niţu ◽  
Doina Iacomi
Keyword(s):  
Numerical Simulation ◽  
Plastic Deformation ◽  
Constitutive Equation ◽  
High Strain ◽  
Modern Method ◽  
Cold Plastic Deformation ◽  
Compression Tests ◽  
Deformation Processes ◽  
Strain Relationship

Numerical Simulationis a Modern Method to Optimize Cold Plastic Deformation Processes in Order Toprovide Product Quality, Reduction of Time and Costs of Execution. One of Theimportant Problems of Numerical Simulation is the Mode of Characterizing Theplastic Behaviour of the Material which Undergoes Deformation. the Resultsobtained through Simulation are Closer to Real Ones as the Description Ofmaterial Behaviour of the Piece is Done as Accurately as Possible. Thesimulation Results Depend on the Stress-Strain Relationship which is Obtainedexperimentally by Compression Tests. the Paper Presents the Mode of Determiningthe Constitutive Equation Starting from the Results of the Compression Test.This Test was Used because it Allows Achieving High Strain and the Stressdistribution is Similar to other Corresponding Plastic Deformation Processes.

Phase Transformations in Pearlitic Steels Induced by Severe Plastic Deformation

2006 ◽  
Vol 114 ◽  
pp. 133-144 ◽  
Author(s):  
Julia Ivanisenko ◽  
Ian MacLaren ◽  
Xavier Sauvage ◽  
Ruslan Valiev ◽  
Hans Jorg Fecht
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Phase Transformations ◽  
High Pressure Torsion ◽  
Pearlitic Steel ◽  
Carbon Steels ◽  
Coarse Grained ◽  
Cold Plastic Deformation ◽  
The Stability ◽  
Nanocrystalline Ferrite

The paper presents an overview of a number of unusual phase transformations which take place in pearlitic steels in conditions of the severe deformation, i.e. combination of high pressure and strong shear strain. Strain-induced cementite dissolution is a well-documented phenomenon, which occurs during cold plastic deformation of pearlitic steels. Recently new results which can shed additional light on the mechanisms of this process were obtained thanks to 3DAP and HRTEM investigations of pearlitic steel deformed by high pressure torsion (HPT). It was shown that the process of cementite decomposition starts by carbon depletion from the carbides, which indicates that the deviation of cementite’s chemical composition from the stoichiometric is the main reason for thermodynamic destabilisation of cementite during plastic deformation. Important results were obtained regarding the distribution of released carbon atoms in ferrite. It was experimentally confirmed that carbon segregates to the dislocations and grain boundaries of nanocrystalline ferrite. Another unusual phase transformation taking place in nanocrystalline pearlitic steel during room temperature HPT is a stress induced α→γ transformation, which never occurs during conventional deformation of coarse grained iron and carbon steels. It was concluded that this occurred due to a reverse martensitic transformation. The atomistic mechanism and the thermodynamics of the transformation, as well as issues related to the stability of the reverted austenite will be discussed.

Experimental Determination of the Yield Stress for Copper, Cu_99.75

2014 ◽  
Vol 659 ◽  
pp. 40-45 ◽  
Author(s):  
Alin Marian Cazac ◽  
Diana Antonia Gheorghiu ◽  
Constantin Baciu ◽  
Stefan Lucian Toma ◽  
Carmen Bujoreanu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Ambient Temperature ◽  
Experimental Determination ◽  
Yield Stress ◽  
Degree Of Deformation ◽  
Deformation Simulation ◽  
Deformation Processes

The paper presents the determination of the yield stress for copper, Cu_99.75, at standard ambient temperature, by means of upsetting of cilyndrical specimens, taking account the allowable degree of deformation of this material. The outcomes achieved can be used both plastic deformation processes and volumic deformation simulation of copper Cu_99.75.

scholarly journals Elastic-plastic state of a short-circular cylinder subjected to axesymmetrical complex loading

1995 ◽  
Vol 17 (1) ◽  
pp. 1-8
Author(s):  
Vu Khac Bay
Keyword(s):  
Plastic Deformation ◽  
Numerical Solution ◽  
Iteration Method ◽  
Complex Loading ◽  
Plastic State ◽  
Space Problem ◽  
Elastic Plastic ◽  
Modified Method ◽  
Deformation Processes ◽  
The Stability

The modified method of elastic solution in the theory of elastic-plastic deformation processes had been proposed in [1]. Through the numerical solution of some elastic-plastic plane problems, the convergence, the convergence rate and the stability of this iteration method had been considered [3, 4]. In this paper, also through the numerical solution of the elastic-plastic space problem, the characters of this iteration method are considered, and the influence of complex loading processes to elastic-plastic state is confirmed.

Experimental Determination of Stress and Deformation Pressure in Nanostructuring Copper by Multiaxial Forging Method

2015 ◽  
Vol 754-755 ◽  
pp. 784-788 ◽  
Author(s):  
Costică Bejinariu ◽  
Alin Marian Cazac ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Andrei Victor Sandhu ◽  
Petru Lazar
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Experimental Determination ◽  
Deformation Process ◽  
Cold Forging ◽  
Total Stress ◽  
Deformation Processes ◽  
Stress And Deformation

This paper aims to determine by experiment total stress and pressure of deformation depending on punch stroke and the level of deformation on severe plastic deformation of copper Cu_99.75 by multiaxial cold forging. The deformation process is discontinuous and includes deformation processes that define a cycle of severe plastic deformation. This paper aims to determine the stress and pressure corresponding to the first 12 cycles of severe plastic deformation.

MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 13. DETERMINATION OF DEFORMED STATE UNDER STRAITENED EXTRUSION IN FOURTH CENTRAL AREA OF PLASTIC DEFORMATION

2020 ◽  
Vol 0 (4) ◽  
pp. 43-51
Author(s):  
A. L. Vorontsov ◽  
◽  
I. A. Nikiforov ◽  
Keyword(s):  
Plastic Deformation ◽  
Plastic Flow ◽  
Central Area ◽  
Direct Extrusion ◽  
Deformed State ◽  
Cumulative Deformation ◽  
The Given ◽  
General Method

Formulae have been obtained that are necessary to calculate cumulative deformation in the process of straitened extrusion in the central area closed to the working end of the counterpunch. The general method of plastic flow proposed by A. L. Vorontsov was used. The obtained formulae allow one to determine the deformed state of a billet in any point of the given area. The formulae should be used to take into account the strengthening of the extruded material.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*
Keyword(s):  
Stability Constant ◽  
Trace Amount ◽  
Benzenesulfonic Acid ◽  
Determination Method ◽  
Blood Samples ◽  
Determination Of Nickel ◽  
Normal Human ◽  
The Stability ◽  
Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 

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