High strain rate

Hoover W G, Ladd A J C and Moran B 1982 High strain rate plastic flow studied via nonequilibrium molecular dynamics Phys. Rev.L 48 1818-20... 

J. L. Edwards, B. H. Cranston, and G. Krauss, Metallic Fffects at High Strain Rates, Plenum Press, New York, 1973. 

Another type of experiment involves a fluid filament being drawn upward against gravity from a reservoir of the fluid (101,213,214), a phenomenon often called the tubeless siphon. The maximum height of the siphon is a measure of the spinnabiUty and extensional viscosity of the fluid. Mote quantitative measures of stress, strain, and strain rate can be determined from the pressure difference and filament diameter. A more recent filament stretching device ia which the specimen is held between two disks that move apart allows measurements ia low viscosity Hquids (215). AH of these methods are limited to spinnable fluids under small total strains and strain rates. High strain rates tend to break the column or filament. 

There is another technique that can be used with low viscosity (100 mPa-s) nonspinnable fluids and which allows high strain rates (>10 ). A... 

Rohde, R.W., B.M. Butcher, D.R. Holland, and C.H. Karnes (1973), Metallurgical Effects At High Strain Rates, Plenum, New York. 

Murr, L.E. (1981), Shock Waves and High-Strain-Rate Phenomena in Metals, Plenum, New York, pp. 1-1101. 

This phenomena has been attributed to the very high strain rates associated with shock loading and the subsonic restriction on dislocation velocity requiring the generation and storage of a larger dislocation density during the shock process than for quasi-static processes [1], [2], [12],... 

L.E. Murr, Metallurgical Effects of Shock and High-Strain-Rate Loading, in Materials at High Strain Rates (edited by T.Z. Blazynski), Elsevier/Applied Science, London, 1987, p. 1. 

P.S. Follansbee, High-Strain-Rate Deformation Mechanisms in Copper and Implications for Behavior during Shock-Wave Deformation, in Shock Waves in Con-... 

L.E. Murr, Effects of Peak Pressure, Pulse Duration, and Repeated Loading on the Residual Structure and Properties of Shock Deformed Metals and Alloys, in Shock Waves and High-Strain-Rate Phenomena in Metals (edited by M.A. Meyers and L.E. Murr), Plenum, New York, 1981, 753 pp. 

J.W. Swegle and D.E. Grady, Calculation of Thermal Trapping in Shear Bands, in Metallurgical Applications of Shock-Wave and High-Strain-Rate Phenomena (edited by L.E. Murr, K.P. Staudhammer, and M.A. Meyers), Marcel Dekker, New York, 1986, pp. 705-722. 

P.S. Follansbee, The Rate Dependence of Structure Evolution in Copper and its Influence on the Stress-Strain Behavior at Very High Strain Rates, in Impact Loading and Dynamic Behavior of Materials (edited by C.Y. Chiem, H.-D. Kunze, and L.W. Meyer), Springer-Verlag, New York, 1988, pp. 315-322, Vol. 1. 

A. Kumar, F.E. Hauser, and J.E. Dorn, Viscous Drag on Dislocations in Aluminum at High Strain Rates, Acta Metall 16, 1189-1197 (1968). 

Karnes, C.H., The Plate Impact Configuration for Determining Mechanical Properties of Materials at High Strain Rates, in Mechanical Behavior of Materials Under Dynamic Loads (edited by Lindholm, U.S.), Springer-Verlag, New York, 1968, pp. 270-293. 

Although the glassy resins form the continuous phase quite high extensions are possible in tensile tests, particularly at high strain rates. 

Equations (5.21), (5.22) and (5.23) are useful for the high strain rates experienced in injection moulding or extrusion but unfortunately they do not predict the low strain rate situation very well where plastic melts tend towards Newtonian behaviour (ie n -) 1). This is illustrated in Fig. 5.7. 

However, for the high strain rates appropriate for the analysis of typical extrusion and injection moulding situations it is often found that the simple Power Law is perfectly adequate. Thus equations (5.22), (5.23) and (5.27) are important for most design situations relating to polymer melt flow. 

In many cases, less intense pressure or stress waves are encountered in which times to achieve peak pressure may be hundreds of nanoseconds or more. The study of solids under these conditions can be the source of mechanical, physical, and chemical properties of solid materials at large strain, high pressure, and high strain rates. 

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