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.

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.

Determination of the geometric parameters of the matrix during the volumetric compression of tin bronze bushings

2021 ◽  
pp. 27-30
Author(s):  
Keyword(s):  
Plastic Deformation ◽  
Compression Ratio ◽  
Geometric Parameters ◽  
Degree Of Deformation ◽  
Deformation Parameters ◽  
Tin Bronze ◽  
The Matrix ◽  
Successful Reduction

The study of the influence of the geometric parameters of the matrix on the quality of the process of reduction of bushings made of tin bronze is carried out. It is established, that for successful reduction plastic deformation should not exceed 10÷15 %, and the angle of the intake part of the crimping matrix should be within 25÷45°, a further increase in this angle significantly reduces the quality of the process. It is shown, that the angle of the lead-in part of the crimping matrix has an insignificant influence on the limiting compression ratio of the bushings, and an increase in the friction coefficient does not significantly affect the deformation parameters. Keywords: bushing, crimping matrix, plastic deformation, compression ratio, wrinkling, degree of deformation [email protected]

An attempt to categorize yield stress fluid behaviour

2009 ◽  
Vol 367 (1909) ◽  
pp. 5139-5155 ◽  
Author(s):  
Peder Moller ◽  
Abdoulaye Fall ◽  
Vijayakumar Chikkadi ◽  
Didi Derks ◽  
Daniel Bonn
Keyword(s):  
Shear Stress ◽  
Experimental Determination ◽  
Yield Stress ◽  
Shear Banding ◽  
Ongoing Debate ◽  
Yield Stress Fluids ◽  
Dense Suspensions ◽  
Experimental Protocols ◽  
Fluid Behaviour

We propose a new view on yield stress materials. Dense suspensions and many other materials have a yield stress—they flow only if a large enough shear stress is exerted on them. There has been an ongoing debate in the literature on whether true yield stress fluids exist, and even whether the concept is useful. This is mainly due to the experimental difficulties in determining the yield stress. We show that most if not all of these difficulties disappear when a clear distinction is made between two types of yield stress fluids: thixotropic and simple ones. For the former, adequate experimental protocols need to be employed that take into account the time evolution of these materials: ageing and shear rejuvenation. This solves the problem of experimental determination of the yield stress. Also, we show that true yield stress materials indeed exist, and in addition, we account for shear banding that is generically observed in yield stress fluids.

scholarly journals EXPERIMENTAL DETERMINATION OF CONDENSER LENGTH EFFECT ON THE THERMOSYPHON PERFORMAN

2019 ◽  
Vol 19 (3) ◽  
pp. 17
Author(s):  
Talib, Z. Farge ◽  
Sahar, R. Al-Sakini ◽  
Aseel, A. Ismael
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Ambient Temperature ◽  
Experimental Determination ◽  
Heat Dissipation ◽  
Filling Ratio ◽  
Transformer Oil ◽  
Working Fluid ◽  
Length Effect

ABSTRACTIn the current work, a thermosyphon was used to investigate the effect of condenser length on its performance. Experimentally by using a pipe of copper having same evaporator length of 120 mm and three different condenser lengths which were 400 mm , 500 mm and 600 mm. The internal and external diameters of the thermosyphon were 26 mm and 28 mm respectively. The evaporator part of the thermosyphon was immersed in the electrical transformer oil, which heated by external heater from ambient temperature to approximately 80 oC, while the condenser part was left to cool naturally by air. Five thermocouples were located on the thermosyphon wall to read the temperature distribution at different positions. The working fluid was water with filling ratio of 50%.The results have obviously shown that temperature gradient was decreased when the condenser length increased and giving a better performance for heat dissipation. The percentage of temperature gradient was positively correlated to the condenser length and it was found that condenser length of ( 400 , 500 , 600) mm gave percentage of decreasing temperature gradient are 67.94 % , 72.94 % , and 77.06 % respectively with respect to that without using thermosyphon .

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.

Experimental determination of a state equation for dissipative granular gases

1999 ◽  
Vol 96 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
E. Falcon ◽  
S. Fauve ◽  
C. Laroche
Keyword(s):  
Experimental Determination ◽  
State Equation ◽  
Granular Gases
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