Driving-stress waveform and the determination of rock internal friction by the stress--strain curve method

Abstract 1. An apparatus is described for measuring the modulus and resilience of rubber over a wide range of frequencies. 2. These measurements can be made at any point in the stress-strain curve of the sample. 3. By increasing the power input, the same apparatus can be used to induce high frequency fatigue in the sample. 4. The earlier work with the torsion head apparatus has been confirmed, namely, that internal friction is greatest near zero strain. 5. High frequency resilience is more independent of degree of vulcanization than tripsometer resilience. 6. Modulus tends to increase with frequency. The effect is least with a rubber gum stock and is greater with compounds containing gas black. 7. Resilience decreases with frequency both in gum and gas black compounds. The decrease is more rapid in the gum compounds. 8. Viscous resistance decreases with frequency and becomes constant at higher frequencies. 9. The modulus of both rubber and Neoprene carbon black compounds decreases with fatigue. 10. The change in modulus with frequency in fatigued stocks is exactly analogous to the change before fatigue in rubber, but there is a slight divergence in the case of Neoprene.

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DETERMINATION OF TRUE STRESS–STRAIN CURVE FOR INCOMPRESSIBLE MATERIALS

Experimental Techniques ◽

10.1111/j.1747-1567.1987.tb00667.x ◽

1987 ◽

Vol 11 (7) ◽

pp. 12-14

Author(s):

J. Vossoughi

Keyword(s):

Strain Curve ◽

True Stress ◽

Stress Strain Curve ◽

Stress Strain ◽

Incompressible Materials

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Metallic materials. Sheet and strip. Determination of biaxial stress-strain curve by means of bulge test with optical measuring systems

10.3403/30254283u ◽

2015 ◽

Cited By ~ 2

Keyword(s):

Strain Curve ◽

Biaxial Stress ◽

Bulge Test ◽

Metallic Materials ◽

Stress Strain Curve ◽

Stress Strain ◽

Measuring Systems ◽

Optical Measuring

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

Rubber Chemistry and Technology ◽

10.5254/1.3547034 ◽

1950 ◽

Vol 23 (3) ◽

pp. 576-580 ◽

Cited By ~ 4

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.

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Determination of Plastic Properties of Polycrystalline Metallic Materials by Nanoindentation – Experiments and Finite Element Simulations

MRS Proceedings ◽

10.1557/proc-841-r11.4 ◽

2004 ◽

Vol 841 ◽

Cited By ~ 1

Author(s):

Karsten Durst ◽

Björn Backes ◽

Mathias Göken

Keyword(s):

Finite Element ◽

Strain Curve ◽

Finite Element Simulations ◽

Metallic Materials ◽

Stress Strain Curve ◽

Stress Strain ◽

Plastic Properties ◽

Ultrafine Grained ◽

Indentation Tests

ABSTRACTThe determination of plastic properties of metallic materials by nanoindentation requires the analysis of the indentation process and the evaluation methods. Particular effects on the nanoscale, like the indentation size effect or piling up of the material around the indentation, need to be considered. Nanoindentation experiments were performed on conventional grain sized (CG) as well as on ultrafine-grained (UFG) copper and brass. The indentation experiments were complemented with finite element simulations using the monotonic stress-strain curve as input data. All indentation tests were carried out using cube-corner and Berkovich geometry and thus different amount of plastic strain was applied to the material, according to Tabors theory. We find an excellent agreement between simulations and experiments for the UFG materials from which a representative strain of εB ≈ 0.1 and εcc ≈ 0.2 is determined. With these data, the slope of the stress-strain curve is predicted for all materials down to an indentation depth of 800 nm.

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