Methods of testing vulcanized rubber. Determination of tensile stress-strain properties

1956 ◽  
Keyword(s):  
Tensile Stress ◽  
Stress Strain ◽  
Vulcanized Rubber

Thermodynamics of Crystallization in High Polymers. VI. Incipient Crystallization in Stretched Vulcanized Rubber

1950 ◽  
Vol 23 (3) ◽  
pp. 576-580 ◽  
Author(s):  
Thomas G. Fox ◽  
Paul J. Flory ◽  
Robert E. Marshall
Keyword(s):  
Theoretical Prediction ◽  
Experimental Determination ◽  
Strain Curve ◽  
Steep Slope ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Hydrostatic Method ◽  
Vulcanized Rubber ◽  
High Polymers

Abstract Experimental determination of the elongation at which crystallization commences in vulcanized rubber has been attempted through measurement of density changes by a hydrostatic method. The critical elongation for incipient crystallization appears to depend on the temperature, in approximate accordance with theoretical prediction. Crystallization sets in at an elongation well below that at which the stress-strain curve assumes a steep slope.

Influence of Repeated Tensile Stress on Determining the Critical Tensile Stress/Strain of Copper Reinforced Bi-2223/Ag Tapes

2013 ◽  
Vol 745-746 ◽  
pp. 219-224
Author(s):  
Li Wei Jing ◽  
Guo Min Zhang ◽  
Jin Cheng Li ◽  
Xin Wu ◽  
Qi Liu
Keyword(s):  
Tensile Stress ◽  
Mechanical Stress ◽  
Transport Property ◽  
Critical Current ◽  
Electrical Transport ◽  
Critical Stress ◽  
Stress Strain ◽  
N Value ◽  
Practical Applications

Critical stress/strain is an important parameter to describe the transport property of superconductors under mechanical stress. The critical stress/strain of specified superconductor should be gotten before the superconductor is applied to manufacture devices. Determination of the critical stress/strain of specified superconductor is related to the chosen reduction percentage of the critical current under monotonic mechanical stress. However, in practical applications, superconductor also withstands repetitive mechanical stresses. Therefore, the influence of repetitive mechanical stress on the critical current or N value should be considered when the critical stress/strain of the superconductor is determined. Therefore, in this paper, the electrical transport property of copper reinforced Bi-2223/Ag tapes under both monotonic and repetitive tensile stress was studied theoretically and experimentally. Based on analysis of the change of critical current and N value under monotonic and different repetitive tensile stresses, the critical stress and strain of this superconductor tape were proposed.

A New Physical Test for Vulcanized Rubber

1929 ◽  
Vol 2 (2) ◽  
pp. 308-317
Author(s):  
D. D. Wright
Keyword(s):  
Tensile Stress ◽  
Standard Procedure ◽  
Combined Effects ◽  
Stress Strain ◽  
Physical Test ◽  
Tensile Stresses ◽  
Vulcanized Rubber

Abstract This test, by use of a sample of new design, subjects rubber to a combination of tensile and shearing stresses. Shear, however, is the predominating stress. Certain aged inner tubes have been found which deteriorated more when examined by this test than a comparison of their tensile-stress-strain curves with those of fresh tubes would indicate. Tearing action seems to be approximated by this test. The effect of overcure in some cases has been recorded at earlier stages by this test than by the tensile criterion. The test is easy to perform and with usual precautions should have an accuracy of approximately 10 per cent. VULCANIZED rubber is frequently required to withstand, not only the simple stresses such as those of compression, tensile, and shear, but also the combined effects such as torsion, tearing, bending, etc. It has been observed that, as some vulcanized rubber samples age, their resistance to shearing and tearing stresses decreases much faster than their resistance to tensile stresses, as determined under the standard procedure of rubber-testing.

scholarly journals Experimental analysis of the mechanical characteristics of launch vehicle parts manufactured by FDM additive technologies

2021 ◽  
Vol 2021 (1) ◽  
pp. 92-100
Author(s):  
I. Derevianko ◽  
◽  
K. Avramov ◽  
B. Uspensky ◽  
A. Salenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Experimental Determination ◽  
Mechanical Characteristics ◽  
Additive Technologies ◽  
Polymer Materials ◽  
Stress Strain ◽  
Shear Moduli ◽  
Young’S Moduli

Additive manufacturing is very promising for aerospace engineering and aircraft construction. Using these technologies, light structures with preset strength properties can be made. For lack of tables of the mechanical properties of materials made by additive technologies, any calculation must be accompanied by the experimental determination of their mechanical properties. This paper presents an experimental approach to the determination of the mechanical characteristics of parts printed by FDM technologies. Parts manufactured from polymers by FDM technologies are shown to be orthotropic. Therefore, their elastic properties are described by nine constants: three Young’s moduli, three shear moduli, and three Poisson ratios. A cube is printed for the experimental determination of these constants. Six specimens are cut out from the cube. Three specimens are cut parallel to the cube edges, and the other three are cut at an angle of 45° to them. Each such specimen is manufactured in five pieces. This makes it possible to average the tensile stress–strain diagrams obtained for all the components of the stress tensor. The mechanical properties of the material are determined from these diagrams. The three Young’s moduli and the three Poisson ratios are determined from the three specimen types parallel to the cube edges. The three shear moduli are determined from the specimens cut at an angle of 45° to the cube edges. To determine these constants, tensile stress–strain diagrams are obtained experimentally. A technology is presented for manufacturing specimens on a Stratasys FORTUS 900 MC 3D printer. The mechanical properties of two polymer materials (ULTEM 9085 and PLA) are determined and compared. PLA has higher Young’s moduli and shear moduli and lower Poisson ratios than ULTEM 9085.

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