Unit for calibration of annular parts by plastic extension

1987 ◽  
Vol 23 (2) ◽  
pp. 80-81
Author(s):  
V. A. Bubnov ◽  
V. A. Votinov
Keyword(s):  
Plastic Extension

scholarly journals IV. Researches on the elastic properties and the plastic extension of metals

1921 ◽  
Vol 221 (582-593) ◽  
pp. 117-138 ◽  
Keyword(s):  
Elastic Properties ◽  
Test Piece ◽  
Plastic Extension

On March 7, 1912, I described an instrument which gives photographically a load-extension diagram of a metal test piece during the process of stretching it to fracture. On February 13, 1913, I described further experiments with the instrument. A diagram was shown which was taken from a test piece broken in ten seconds. It is safe to say that up to that time no apparatus existed which would give a complete record of the load-extension relation during such a quick break.

Indentation size effects in polymers and related rotation gradients

2007 ◽  
Vol 22 (6) ◽  
pp. 1662-1672 ◽  
Author(s):  
Chung-Souk Han ◽  
Svetoslav Nikolov
Keyword(s):  
Experimental Data ◽  
Size Effects ◽  
Indentation Size Effect ◽  
Polymer Chains ◽  
Indentation Size ◽  
Proposed Model ◽  
Dislocation Densities ◽  
Model Size ◽  
Depth Ranges ◽  
Plastic Extension

Similar to metals, the hardness of many polymers increases with decreasing indentation depths at depth ranges from several microns down to several nanometers. While for metals such phenomena are commonly attributed to geometrically necessary dislocation densities, such an explanation cannot be applied to polymers. To provide a micromechanically motivated model for the indentation size effect in polymers, here we propose an elasto-plastic extension of the higher order elasticity model recently developed by the authors. In this model, size effects in polymers (as well as in nematic liquid crystals) are related to Frank elasticity arising from bending distortions of the polymer chains and their interactions. On the basis of this theory, we derive a simple model for indentation size effects in polymers. Unlike other models, our model includes only elastic size effects due to rotational gradients. It is shown that the proposed model can explain the experimentally observed size effects in polymers. Together with the existing experimental data mentioned here, new experimental data for silicon rubber are also presented and discussed.

scholarly journals THE EFFECT OF POLYPHOSPHATES AND MAGNESIUM ON THE MECHANICAL PROPERTIES OF EXTRACTED MUSCLE FIBERS

1956 ◽  
Vol 39 (5) ◽  
pp. 789-800 ◽  
Author(s):  
Emil Bozler
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Modulus Of Elasticity ◽  
Muscle Fibers ◽  
Configurational Entropy ◽  
Partial Removal ◽  
Relaxation Factor ◽  
Low Concentrations ◽  
Strong Contraction ◽  
Plastic Extension

Loading of extracted muscle fibers causes a small, sudden lengthening, followed by a slower, plastic extension, which is reversed only by active contraction. Polyphosphates in the presence of Mg strongly accelerate plastic extension, but elastic changes in length remain the same as during rigor. The modulus of elasticity on the average is about 6.2 x 107 dynes per cm.2 This value is about 40 times larger than that of rubber, if compared on a water-free basis. Extension of muscle, therefore, is almost entirely due to plastic deformation. Mg is essential for the softening action of adenosinetriphosphate (ATP) and can produce partial relaxation in the absence of a relaxation factor. After partial removal of bound Mg, ATP causes strong contraction, but only slight softening. The same condition is produced by very low concentrations of ATP in the presence of phosphocreatine. These observations show that during contraction passive mechanical properties may remain essentially like those during rigor. The constancy of elastic extensibility distinguishes contraction produced by ATP from contraction induced by non-specific agents in various fibrous structures and caused by an increase in configurational entropy.

scholarly journals The heat developed during plastic extension of metals

1925 ◽  
Vol 107 (743) ◽  
pp. 422-451 ◽  
Keyword(s):  
Phase Change ◽  
Internal Energy ◽  
Amorphous Material ◽  
Soft Or ◽  
Soft Metal ◽  
The Difference ◽  
Cold Worked ◽  
Work Done ◽  
Annealed Copper ◽  
Plastic Extension

When a soft metal, such as annealed copper or aluminium, is deformed while cold, either by stretching, hammering, rolling, or other method of ‘‘cold working’’ it hardens; that is, the forces necessary to deform it increase as the amount of plastic deformation increases. The physical state of “cold worked’’ metal is undoubtedly different from that of the metal in its original soft or annealed state, and various explanations have been put forward to account for the difference. Some of these explanations involve the hypothesis that the process of hardening is associated with the formation of amorphous material at the crystal planes where slipping occurs during the deformation. The formation of amorphous material from a crystalline mass would involve a phase change, which would in general be accompanied by a change in the internal energy of the material. It has been suggested that the phase change could detected by measuring the heat evolved during a deformation, and com-ring with the heat equivalent of the work done on the metal by the forces inducing the deformation. Any difference between the two would imply change in the internal energy of the metal. It is curious that very few measurements of this type appear to have been inside. The only reference which we have been able to find occurs in Dr. Rosen-Inde article on “ Metals,” in the 4 Dictionary of Physics,5 where he quotes the previously unpublished observations made by Dr. Sinnat.

Measurement of Micro Residual Stresses Near the Grain Boundary in Copper Bicrystal

2010 ◽  
Vol 89-91 ◽  
pp. 515-520
Author(s):  
Ayumi Shiro ◽  
Hanabusa Takao ◽  
Tatsuya Okada ◽  
Nishida Masayuki ◽  
Kazuya Kusaka ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Grain Boundary ◽  
Residual Stresses ◽  
Kink Band ◽  
X Ray ◽  
Kink Bands ◽  
Crystal Orientations ◽  
Plastic Extension ◽  
Compressive Residual Stresses ◽  
Radiation Research

Residual stresses near the grain boundary of a bicrystal were measured by synchrotron radiation of SPring-8 at Japan Synchrotron Radiation Research Institute. A copper bicrystal specimen with a 90-degree tilt boundary was deformed 30% in tension. After the plastic extension, kink bands developed in a deformed matrix along the grain boundary. In this study, we focused on the residual stresses in the deformed matrix and the kink band. Residual stresses were evaluated by the X-ray single crystal measurement method. Stereographic projections were used to determine crystal orientations of deformed regions. Our observation showed that crystal orientations were different between the deformed matrix and the kink band. Residual stresses in the direction along the grain boundary in the deformed matrix and kink band were compressive. Residual stresses in the direction vertical to the grain boundary were seen opposite between the deformed matrix and the kink band.

Plastic Extension of a Plate with Symmetric Notches

2017 ◽  
Vol 52 (5) ◽  
pp. 511-523
Author(s):  
R. I. Nepershin
Keyword(s):  
Plastic Extension

scholarly journals The plastic extension of a chain of rings due to an axial impact load

1978 ◽  
Vol 20 (8) ◽  
pp. 529-538 ◽  
Author(s):  
J.F. Silva-Gomes ◽  
S.T.S. Al-Hassani ◽  
W. Johnson
Keyword(s):  
Impact Load ◽  
Axial Impact ◽  
A Chain ◽  
Plastic Extension
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