Mechanical Properties at Small Deformations

2014 ◽  
pp. 381-438
Keyword(s):  
Mechanical Properties ◽  
Small Deformations

Mechanical properties of steel 20 at small deformations

2015 ◽  
Vol 57 (8) ◽  
pp. 1569-1573 ◽  
Author(s):  
B. G. Mytsyk ◽  
Ya. P. Kost’ ◽  
B. I. Turko ◽  
G. I. Gas’kevich
Keyword(s):  
Mechanical Properties ◽  
Steel 20 ◽  
Small Deformations

scholarly journals Nanomechanical properties of enucleated cells: contribution of the nucleus to the passive cell mechanics

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Yuri M. Efremov ◽  
Svetlana L. Kotova ◽  
Anastasia A. Akovantseva ◽  
Peter S. Timashev
Keyword(s):  
Mechanical Properties ◽  
Cell Mechanics ◽  
Normal Cells ◽  
Force Microscopy ◽  
Nanomechanical Properties ◽  
Atomic Force ◽  
Fibrosarcoma Cells ◽  
Actomyosin Cytoskeleton ◽  
Small Deformations

Abstract Background The nucleus, besides its functions in the gene maintenance and regulation, plays a significant role in the cell mechanosensitivity and mechanotransduction. It is the largest cellular organelle that is often considered as the stiffest cell part as well. Interestingly, the previous studies have revealed that the nucleus might be dispensable for some of the cell properties, like polarization and 1D and 2D migration. Here, we studied how the nanomechanical properties of cells, as measured using nanomechanical mapping by atomic force microscopy (AFM), were affected by the removal of the nucleus. Methods The mass enucleation procedure was employed to obtain cytoplasts (enucleated cells) and nucleoplasts (nuclei surrounded by plasma membrane) of two cell lines, REF52 fibroblasts and HT1080 fibrosarcoma cells. High-resolution viscoelastic mapping by AFM was performed to compare the mechanical properties of normal cells, cytoplasts, and nucleoplast. The absence or presence of the nucleus was confirmed with fluorescence microscopy, and the actin cytoskeleton structure was assessed with confocal microscopy. Results Surprisingly, we did not find the softening of cytoplasts relative to normal cells, and even some degree of stiffening was discovered. Nucleoplasts, as well as the nuclei isolated from cells using a detergent, were substantially softer than both the cytoplasts and normal cells. Conclusions The cell can maintain its mechanical properties without the nucleus. Together, the obtained data indicate the dominating role of the actomyosin cytoskeleton over the nucleus in the cell mechanics at small deformations inflicted by AFM.

Mechanical properties of polymers

1964 ◽  
Vol 282 (1388) ◽  
pp. 115-120 ◽  
Keyword(s):  
Mechanical Properties ◽  
Point Of View ◽  
Visual Examination ◽  
Linear Relations ◽  
Physical Description ◽  
Additional Information ◽  
Physical Measurements ◽  
Linear Behaviour ◽  
Properties Of Materials ◽  
Small Deformations

A physicist talking on mechanical properties of materials will obviously start from the properties which are simplest from the point of view of a mathematical physical description. These are the properties exhibited by the material at small deformations, so small that linear relations exist between the deformation and the stress. This linear behaviour of materials can be described completely by two functions of time. For larger deformations and particularly for the behaviour at rupture a complete physical description has not yet been obtained and the difficulties involved in reaching such a description are tremendous. However, the engineer is most particularly interested in those latter properties, and although the information obtainable from physical measurements in this field is very incomplete, additional information and insight can be acquired with the methods of the biologist , i. e. by visual examination with an appropriate microscope.

scholarly journals Evaluation of the behavior of mortars produced with fibers from the straw of carnauba: effects of the content of addition and length used

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Antunes França Eduardo ◽  
Marcilene Vieira de Nóbrega ◽  
Ruan Landolfo da Silva Ferreira
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Deformation Capacity ◽  
Mass Ratio ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Hardened State ◽  
The Stability ◽  
Small Deformations ◽  
Pathological Manifestation

ABSTRACT The rendering mortars must be able to absorb small deformations, in order to guarantee the stability of the masonry (performance and durability). When this premise is not met, there is a greater propensity for the appearance of cracks, one of the main and worrying pathological manifestations in mortar coverings. One of the alternatives to combat this pathological manifestation is the addition of natural/artificial fibers in order to improve the mechanical properties (mainly the traction strength) and, consequently, the deformation capacity of the mortar. In this perspective, this work analyzed the behavior in the fresh and hardened state of mortars with the addition of fibers obtained from the straw of the carnauba (Copernicia prunifera), an abundant tree in the region of the Açu valley/RN (Brazil). For this purpose, mortars were produced in a 1:3 mass ratio (binder:aggregate) with the addition of 3% and 5% fiber from the carnauba straw (CSF) in relation to the cement mass and with the water/cement ratio (w/c) fixed at 0.72 for all mixtures. The effects of using fibers with different lengths (20, 40 and 60 mm) were also investigated. The properties of mortars were evaluated in a fresh (consistency) and hardened (compression and flexural strengths) state. The results indicated that the addition of CSF results in mortar with less consistency and mechanical strength. However, in general, the best performance was obtained for additions of up to 3% and for longer fiber lengths (20 mm).

Dependence of the Ultimate Properties of a SBR Rubber on Strain Rate and Temperature

1959 ◽  
Vol 32 (4) ◽  
pp. 992-1004 ◽  
Author(s):  
Thor L. Smith
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Temperature Dependence ◽  
Amorphous Polymers ◽  
Shift Factor ◽  
Ultimate Properties ◽  
Tensile Data ◽  
Small Deformations

Abstract The tensile strength and ultimate elongation of polymeric materials depend on both the temperature and experimental time scale. The mechanical properties of amorphous polymers at temperatures above their glass transition temperature Tg are more amenable to treatment in terms of molecular theories than are their mechanical properties at temperatures below Tg or the mechanical properties of crystalline polymers. For amorphous polymers at temperatures above Tg the viscoelastic properties in small deformations have been studied rather extensively, and several molecular theories—essentially identical—have been published. In contrast, few systematic studies have been made of the effect of time and temperature on the ultimate properties. Consequently, only a limited amount of data is available which can serve as a basis for developing and verifying molecular theories dealing with ultimate properties. A recent theory by F. Bueche treats the time and temperature dependence of tensile strength. According to his theory, the tensile strength for a given material is a universal function of a reduced time or a reduced strain rate, except at short times or high strain rates where the material approaches glasslike behavior. Also, to superpose data measured at different temperatures, a shift factor is needed which is determined by the temperature dependence of the frictional factor for polymeric segment mobility and thus is the same factor as used to superpose viscoelastic data measured in small deformations. Thus, according to Bueche's theory, the temperature dependence of the tensile strength is given by the equation of Williams, Landel, and Ferry which is applicable in the temperature range Tg<T<(Tg+100). Bueche reported some tensile data for polybutyl methacrylate which has a glass transition temperature of 8° C. These tensile data were measured under various constant loads at temperatures between 30 and 95° C, and reasonable agreement between theory and experiment was found. Although Bueche did not consider the ultimate elongation, it seems reasonable that such data can be superposed by using the same shift factor as required to superpose the tensile strength data. Other workers have not considered explicitly the effect of viscous forces on the ultimate properties but have considered the effect of such variables as molecular weight, degree of crosslinking, and plasticizers.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

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