Wide range of strain rates

K. Higashi, T. Nakamura, T. Mukai, S. Tanimura, "High temperature deformation characteristics of extruded 2090 Aluminium - Lithium Alloys in a wide range of strain-rate" International Aluminium - Lithium Conference, Garmisch - Partenkirchen, aluminhium -Lithium vol 2. 1114-1116, 1992, Publ Deutsche Gesellschaft fur Materialkunde e.V. Oberursel, Germany. 

The mechanical response of polypropylene foam was studied over a wide range of strain rates and the linear and non-linear viscoelastic behaviour was analysed. The material was tested in creep and dynamic mechanical experiments and a correlation between strain rate effects and viscoelastic properties of the foam was obtained using viscoelasticity theory and separating strain and time effects. A scheme for the prediction of the stress-strain curve at any strain rate was developed in which a strain rate-dependent scaling factor was introduced. An energy absorption diagram was constructed. 14 refs. 

For low viscosity fluids such as dilute polymer solutions, the various stagnation-point devices can prove useful. In this category is the coiiunercially available Rheometrics RFX opposing jet device, a development of earlier instruments [Cathey and Fuller, 1988], which has the potential to produce a wide range of strain rates, and which has been used to study fluids with a viscosity approaching that of water [Hermansky and Boger, 1995]. 

Fig. 1.15 Dependence of the viscosity on a wide range of strain rates in a four-component BMG (Pd4oNiloCu3oP2o) showing clearly strain-rate-induced glass transitions at four different temperatures (from Kato et al. (1998) courtesy of the AIP).

Lu, J., Ramachandran, G., and Johnson, W. L. (2003) Deformation behavior of the Zr4i.2Tii3.8Cui2.5NiioBe22.5 bulk metallic glass over a wide range of strain rates and... 

We demonstrate below that the plastic response to a wide range of strain rates is part of the fundamental plastic relaxations occurring inside shear transformations in atom clusters of substantial size where the shear modulus with its specific dependences merely scales the activation energy for the formation of the actual strain-producing shear transformations. 

Richeton, J., Ahzi, S., Daridon, L., and Remond, Y. (2005) A formulation of the cooperative model for the yield stress of amorphous polymers for a wide range of strain rates and temperatures, Polymer, 46, 6035-6043. 

The usefulness of this model can be evaluated by comparison of calculation results with experimental data obtained for PBU and PDUE (Figures 10.63, 10.64). The model adequately describes the deformation behavior of elastomers in a wide range of strain rates. The main shortcoming of the model is that it does not describe a final stage of deformation of elastomers having S-shape strain curve. 

J A Rodriguez-Martinez, R Pesci, and A Rusinek. Experimental study on the martensitic transformation in aisi 304 steel sheets subjected to tension under wide ranges of strain rate at room temperature. Materials Science and Engineering A, 528(18) 5974—5982, 2011. 

Khan AS, Lopez-Pamies O, Kazmi R (2006) Thermo-mechanical large deformation response and constitutive modeling of viscoelastic polymers over a wide range of strain rates and temperatures. Int J Plast 22 581-601... 

Ti-15-3 has been studied at temperatures of 850 and 760 to determine flow di acteristics and potential superplastic formabilily. Specimens were tested in the as-received condition and, as such, had a grain size of about 80 pm. It is found that this alloy exhibits d ormation behavior quite different horn the two-phcuse alloys in that it tends to flow soften with about 2 to 4% strain (see figure). The softening is reflected in the stress vs strain-rate diaracteristics, where the prestrain can be seen to reduce the flow stresses and increase the strain-rate sensitivity observed over a wide range of strain rates. 

This relationship, known as the Trouton ratio, is valid at low stresses or rates. Figure 8.26 compares the elongational viscosity-stretch rate (e) relationship to the shear viscosity-shear rate relationship over a wide range of strain rates. At low rates, the elongational viscosity is three times of the shear viscosity. Shear... 

Instruments Extensional Viscosity Fixture (EVF). The EVF measmes the extensional viscosity as a function of time over a wide range of strain rates relevant to polymer processing. For all experiments, the temperatures at which the tests are performed range Sum 155°C to 185°C. In addition, an inert nitrogen atmosphere is used for all testing. 

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