Strain ratio and volume change during tension and compression creep of thermoplastics

1972 ◽  
Vol 12 (6) ◽  
pp. 420-424 ◽  
Author(s):  
P. J. Mallon ◽  
D. McCammond ◽  
P. P. Benham
Keyword(s):  
Volume Change ◽  
Strain Ratio ◽  
Compression Creep ◽  
Tension And Compression

scholarly journals Influence of Normal Stress on Creep in Tension and Compression of Polyethylene and Rigid Polyvinyl Chloride Copolymer

1962 ◽  
Vol 84 (2) ◽  
pp. 237-246 ◽  
Author(s):  
D. G. O’Connor ◽  
W. N. Findley
Keyword(s):  
Normal Stress ◽  
Polyvinyl Chloride ◽  
Material Structure ◽  
Reasonable Accuracy ◽  
Creep Tests ◽  
Compression Creep ◽  
Cent Relative Humidity ◽  
Tension And Compression ◽  
New Apparatus ◽  
Shear Planes

New apparatus suitable for compression creep tests of slender specimens is described. The apparatus is designed to prevent buckling and to introduce a minimum of friction. Results are reported for tension and compression creep of polyethylene and annealed, unplasticized polyvinyl chloride copolymer at 75 deg F and 50 per cent relative humidity. The stress σ, strain ε, time t data from these tests were found to be describable with reasonable accuracy by the equation ε=ε0′sinhσ/σε+m′tnsinhσ/σm where ε0′, m′, n, σε, and σm are material constants. The results for polyethylene show that the creep in tension and compression were virtually the same. However, the creep in tension was similar but larger than in compression for polyvinyl chloride. These observations are interpreted in terms of the material structure and the influence of the normal stress on active shear planes.

Tension and Compression Creep Apparatus for Wood–Plastic Composites

2011 ◽  
Vol 39 (6) ◽  
pp. 103715
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Scott E. Hamel ◽  
John C. Hermanson ◽  
Steven M. Cramer
Keyword(s):  
Wood Plastic Composites ◽  
Compression Creep ◽  
Plastic Composites ◽  
Tension And Compression

Shearing mechanisms of γ' precipitates by dissociated single-matrix dislocations in nickel-based superalloys

1990 ◽  
Vol 48 (4) ◽  
pp. 452-453
Author(s):  
Brigitte Décamps ◽  
Allan J. Morton
Keyword(s):  
Image Matching ◽  
Bright Field Image ◽  
Bright Field ◽  
Weak Beam ◽  
Compression Creep ◽  
Tension And Compression ◽  
Deformation Processes ◽  
Single Matrix ◽  
Shearing Mechanism ◽  
Matching Techniques

Superlattice stacking faults play an important part in the deformation processes of γ/γ' Ni-based superalloys. However, recent studies using the weak-beam technigue have brought into question the previously accepted mechanism for shearing of the γ'precipitates. A new shearing mechanism involving a single a/2<110> matrix dislocation and the nucleation of a Shockley partial has been proposed. In the present study, TEM weak-beam and bright field image matching techniques have been used to study the elementary shearing configurations of γ'precipitates in [001] single crystals of superalloys after creep (intermediate temp.) and dynamical (high temp.) tests in compression and tension.The observations show a change of configurations between compression and tension: in dynamical compression, precipitates are mainly sheared by leading S-ESF (Fig. 1); and in tension creep by leading S-ISF (Fig. 2). Both dynamical tension and compression creep give a mixture of S-ISF and S-ESF.

Microstructural Development in Tension and Compression Creep of Magnesium Alloy AE42

2005 ◽  
Vol 482 ◽  
pp. 271-274 ◽  
Author(s):  
Hajo Dieringa ◽  
Amanda L. Bowles ◽  
Norbert Hort ◽  
Karl Ulrich Kainer
Keyword(s):  
Magnesium Alloy ◽  
Microstructural Development ◽  
Compression Creep ◽  
Tension And Compression

Experimental Research on Constitute Relation of Concrete under Uniaxial Tension and Compression with Different Strain Rate

2011 ◽  
Vol 250-253 ◽  
pp. 3279-3283 ◽  
Author(s):  
Hai Bin Chen ◽  
You Po Su ◽  
Jun Wei Xing ◽  
Yu Min Zhang
Keyword(s):  
Structural Analysis ◽  
Strain Rate ◽  
Uniaxial Tension ◽  
Theoretical Basis ◽  
Strain Curve ◽  
Strain Ratio ◽  
Test Device ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Tension And Compression

The constitutive relation of concrete under uniaxial tension and compression is an essential theoretical basis for structural analysis of concrete. Because of the lack of sufficient stiffness for ordinary test device, a stable decline branch of stress-strain curve could not be obtained. The condition of realizing the stress-strain complete curve for concrete uniaxial tension and compression is derived. The experiment device for uniaxial tension and compression was designed and fabricated with increasing stiffness method. Experiments were carried out for concrete with grade C30~C60 and strain rate 10-5/s~10-2/s. The equation for stress-strain curve in the rising branch were obtained and so were the complete stress-strain curve of uniaxial tension and compression under different strain ratio, which provide the theoretical basis for concrete structural analysis.

scholarly journals High Temperature Behavior of Al-7Si-0.4Mg Alloy with Er and Zr Additions

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 879
Author(s):  
Elisabetta Gariboldi ◽  
Chiara Confalonieri ◽  
Marco Colombo
Keyword(s):  
High Temperature ◽  
Eutectic Silicon ◽  
A356 Alloy ◽  
Minor Element ◽  
High Temperature Strength ◽  
Creep Tests ◽  
Casting Alloys ◽  
Compression Creep ◽  
Tension And Compression

In recent years, many efforts have been devoted to the development of innovative Al-based casting alloys with improved high temperature strength. Research is often oriented to the investigation of the effects of minor element additions to widely diffused casting alloys. The present study focuses on Al-7Si-0.4Mg (A356) alloy with small additions of Er and Zr. Following previous scientific works on the optimization of heat treatment and on tensile strength, creep tests were carried out at 300 °C under applied stress of 30 MPa, a reference condition for creep characterization of innovative high-temperature Al alloys. The alloys containing both Er and Zr displayed a lower minimum creep strain rate and a longer time to rupture. Fractographic and microstructural analyses on crept and aged specimens were performed to understand the role played by eutectic silicon, by the coarse intermetallics and by α-Al matrix ductility. The creep behavior in tension of the three alloys has been discussed by comparing them to tension and compression creep curves available in the literature for Al-7Si-0.4Mg improved by minor elemental additions.

The Effect of Grain Size and SiC Particulates on the Strength and Ductility of MoSi2

1993 ◽  
Vol 322 ◽  
Author(s):  
Amit K. Ghosh ◽  
Ajoy Basu
Keyword(s):  
Grain Size ◽  
Compression Behavior ◽  
Grain Sizes ◽  
Fine Grain ◽  
Compression Creep ◽  
The Matrix ◽  
Tension And Compression ◽  
Sic Particulates ◽  
Ductile To Brittle Transition ◽  
Strength And Ductility

AbstractMonolithic MoSi2 and MoSi2 reinforced with SiC particulate reinforcements have been produced with widely varying grain sizes. Monotonic compression behavior of these materials has been examined in the temperature range of room temperature to 1200°C. Based on these results, the ductile-to-brittle transition temperature at low deformation rate of MoSi2 and its composite appears to be near 900°C and may decrease slightly with decreasing grain size. Tension and compression creep behavior of these materials were also studied between 1100 and 1400°C. Creep strength of the matrix decreases with decreasing grain size even in the nominally dislocation climb-glide regime. While 20 vol% SiC particulates provide a reasonable amount of creep strengthening of the fine grain MoSi2 matrix, strengthening due to coarser grain size can be significantly higher in these materials. These results parallel those on other intermetallics.

scholarly journals Experimental Investigation of the Tension and Compression Creep Behavior of Alumina-Spinel Refractories at High Temperatures

Ceramics ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 372-383
Author(s):  
Lucas Teixeira ◽  
Soheil Samadi ◽  
Jean Gillibert ◽  
Shengli Jin ◽  
Thomas Sayet ◽  
...  
Keyword(s):  
Creep Behavior ◽  
Working Life ◽  
Refractory Materials ◽  
Secondary Creep ◽  
Inverse Identification ◽  
Creep Tests ◽  
Identification Procedure ◽  
Compression Creep ◽  
Experimental Creep ◽  
Tension And Compression

Refractory materials are subjected to thermomechanical loads during their working life, and consequent creep strain and stress relaxation are often observed. In this work, the asymmetric high temperature primary and secondary creep behavior of a material used in the working lining of steel ladles is characterized, using uniaxial tension and compression creep tests and an inverse identification procedure to calculate the parameters of a Norton-Bailey based law. The experimental creep curves are presented, as well as the curves resulting from the identified parameters, and a statistical analysis is made to evaluate the confidence of the results.

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