Elastoplastic transition in the material with sharp yield point

2015 ◽  
Author(s):  
Vadim Gorbatenko ◽  
Vladimir Danilov ◽  
Lev Zuev
Keyword(s):  
Yield Point ◽  
Sharp Yield Point ◽  
Elastoplastic Transition

The Physical Properties of the Pedal Mucus of the Terrestrial Slug, Ariolimax Columbianus

1980 ◽  
Vol 88 (1) ◽  
pp. 375-394 ◽  
Author(s):  
MARK W. DENNY ◽  
JOHN M. GOSLINE
Keyword(s):  
Shear Modulus ◽  
Physical Properties ◽  
Strain Rate ◽  
Yield Stress ◽  
Viscous Liquid ◽  
Yield Point ◽  
Viscoelastic Solid ◽  
Sharp Yield Point ◽  
Small Deformations

The pedal mucus of gastropods functions in locomotion by coupling the movements of the foot to the substratum. The pedal mucus of the terrestrial slug, Ariolimax columbianus, is suited to this role by the following unusual physical properties. 1. At small deformations the mucus is a viscoelastic solid with a shear modulus of 100–300 Pa. 2. The mucus shows a sharp yield point at a strain of 5–6, the yield stress increasing with increasing strain rate. 3. At strains greater than 6 the mucus is a viscous liquid (η = 30–50 poise). 4. The mucus recovers its solidity if allowed to ‘heal’ for a period of time, the amount of solidity recovered increasing with increasing time.

Aspects of Grain Size Strengthening in Polycrystals

2001 ◽  
Vol 683 ◽  
Author(s):  
Dilip Chandrasekaran ◽  
Kjell Pettersson
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Simple Model ◽  
Grain Boundaries ◽  
Yield Point ◽  
Strengthening Effect ◽  
Petch Relationship ◽  
Sharp Yield Point

ABSTRACTThe strengthening effect of grain boundaries is well established and observed experimentally as the Hall-Petch relationship. In this paper different mechanisms proposed in the literature to explain the observed Hall-Petch effect are reviewed critically. The fundamental implications of the different approaches are discussed with reference to experimental data for two different classes of materials;-Materials with locked dislocations, i.e. with a sharp yield point behaviour.-Materials without locked dislocations, i.e. with a smooth yielding behaviour.It is shown that a simple model (Bergström) can be used to understand the grain size strengthening in the latter class of materials while more work is needed to quantitatively understand the behaviour of materials showing a sharp yield point.

A study of the sharp yield point of a Ti-22Al-25Nb alloy

2017 ◽  
Vol 701 ◽  
pp. 727-731 ◽  
Author(s):  
Yingying Zong ◽  
Bin Shao ◽  
Yingtao Tian ◽  
Debin Shan
Keyword(s):  
Yield Point ◽  
Sharp Yield Point

A model of the continuous elastoplastic transition in metals

1971 ◽  
Vol 6 (3) ◽  
pp. 185-192 ◽  
Author(s):  
W J D Jones ◽  
A K Agarwal
Keyword(s):  
Yield Point ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Yield Strain ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Aluminium Copper ◽  
Stress Cycling ◽  
Elastoplastic Transition ◽  
Plastic Parts

Part 1: The heterogeneous character of a real metal is represented by a model in which the metal is considered to consist of a large number of elements with a variation of individual stress-strain responses. The variation of Poisson's ratio which occurs as a function of strain is used to measure the progress of yielding through the material and hence to calculate the variation in elemental yield strains. By use of data obtained from the completely elastic and fully plastic parts of the stress-strain curve and the yield strain distribution, the elastoplastic transition behaviour can be calculated. Comparisons are presented between computed and experimental stress-strain curves for aluminium, copper, magnesium, nickel, and titanium alloy to demonstrate the validity of the proposed model. Part 2: Sufficient cyclic stressing can change the subsequent stress-strain curve of a steel which normally has a yield point into one with a continuous elastoplastic transition. A model of the elastoplastic transition in metals, developed by the authors in Part 1 to represent the stress-strain behaviour of metals with a continuous elastoplastic transition, is then proposed for representing the stress-strain behaviour of steels in which the yield point has been removed, by stress cycling. Results are presented to show good agreement between the model and the observed stress-strain behaviour of four steels, one of which had no yield point and the other three had their yield points removed by cyclic stressing.

A theory of sharp yield point in low-dislocation crystals

2001 ◽  
Vol 46 (11) ◽  
pp. 1389-1395 ◽  
Author(s):  
B. V. Petukhov
Keyword(s):  
Yield Point ◽  
Sharp Yield Point

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

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