Shock-wave measurements

Walsh, J.M., and Christian, R.H. (1955), Equation of State of Metals from Shock Wave Measurements, Phys. Rev. 97, 1544-1556. 

S.P. D yakov, ZhEksp i TeoretFiz 27 (c) 728-34(1954) (in Russian) (Shock waves in a relaxing medium) 29) R.H. Christian et al, JChemPhys 23, 2042-49(1955) (Equation of state of gases by shock wave measurements) 29a) A. Haid, "The Distant Effects of Detonation , Explosivst 3,... 

Ref G.D. Anderson et al, "The Equation of State of 1060 Aluminum From Shock Wave Measurements , 4thONRSympDeton (1965), 213 (Abstract only)... 

Details on the evaluation of shock-wave data are given in many places in the literature therefore, it is sufficient to note here that the determination of a pressure-volume (p-v)-isotherm from shock-wave data is affected not only by uncertainties in the shock-wave measurements but also by problems in the data reduction. Thus, (p-v)-isotherms from shock-wave measurements can be trusted only to within a 5 per cent accuracy at intermediate pressures and only a rigorous intercomparison with first-principle calculations leads to confidence that the pressure calibration realized by various (p-v)-isotherms of specially simple solids represents an absolute scale with an accuracy of better than 5 per cent (in the pressure) up to 1 TPa. ... 

Alsmeyer H (1976) Density profiles in argon and nitrogen shock waves measured by the absorption of an electron beam. J Fluid Mech 74 497-513... 

J. StaudenrausandW. Eisenmenger, Fiher-optic prohe hydrophone for ultrasonic and shock-wave measurements in water. Ultrasonics31(4), 267-273 (1993). 

Cathignol, D. (1990) PVDF hydrophone with liquid electrodes for shock wave measurements, Proceedings of the IEEE Ultrasonics S3miposium, Honolulu, HI, 4-7 December... 

Koch, C., Molkenstruck, W. and Reibold, R. (1997) Shock-wave measurement using a calibrated interferometric fiber-tip sensor. Ultrasound Med. Biol, 23, 1259-66. 

CP, (374C, 221 bar), and triple point, TP, are indicated on the gas-liquid coexistence curve. The points on the broken line extending from TP to the right denote the transitions between different high pressure modifications of ice. At pressures above 25 kbar, water densities have been derived from shock wave measurements ( 7) At 500 C and 1000 C, pressures of about 8 and 20 kbar are needed to produce the triple point density of liquid water. 

When an isotropic material is subjected to planar shock compression, it experiences a relatively large compressive strain in the direction of the shock propagation, but zero strain in the two lateral directions. Any real planar shock has a limited lateral extent, of course. Nevertheless, the finite lateral dimensions can affect the uniaxial strain nature of a planar shock only after the edge effects have had time to propagate from a lateral boundary to the point in question. Edge effects travel at the speed of sound in the compressed material. Measurements taken before the arrival of edge effects are the same as if the lateral dimensions were infinite, and such early measurements are crucial to shock-compression science. It is the independence of lateral dimensions which so greatly simplifies the translation of planar shock-wave experimental data into fundamental material property information. 

Equation-of-state measurements add to the scientific database, and contribute toward an understanding of the dynamic phenomena which control the outcome of shock events. Computer calculations simulating shock events are extremely important because many events of interest cannot be subjected to test in the laboratory. Computer solutions are based largely on equation-of-state models obtained from shock-wave experiments which can be done in the laboratory. Thus, one of the main practical purposes of prompt instrumentation is to provide experimental information for the construction of accurate equation-of-state models for computer calculations. 

These are some of the oldest, yet still the most useful gauges in shock-wave research. They contribute mainly to shock-velocity measurements. In some cases, these gauges alone can provide accurate Hugoniot equation-of-state... 

The objective in these gauges is to measure the time-resolved material (particle) velocity in a specimen subjected to shock loading. In many cases, especially at lower impact pressures, the impact shock is unstable and breaks up into two or more shocks, or partially or wholly degrades into a longer risetime stress wave as opposed to a single shock wave. Time-resolved particle velocity gauges are one means by which the actual profile of the propagating wave front can be accurately measured. 

Shock-compression science originated during and after World War II when experimental facilities for creating planar shock waves were developed, along with prompt instrumentation techniques enabling shock velocity and particle velocity measurements to be made. The main thrust of shock-compression science is to understand the physics and to measure the material properties which govern the outcome of shock-compression events. Experiments involving planar shock waves are the most useful in shock-compression science. 

Grady, D.E. (1986), Eligh-Pressure Release-Wave Measurements and Phase Transformation in CaCOj, in Shock Waves in Condensed Matter (edited by Y.M. Gupta), Plenum, New York, pp. 589-594. 

In this chapter we define what is meant by a shock-wave equation of state, and how it is related to other types of equations of state. We also discuss the properties of shock-compressed matter on a microscopic scale, as well as discuss how shock-wave properties are measured. Shock data for standard materials are presented. The effects of phase changes are discussed, the measurements of shock temperatures, and sound velocities of shock materials are also described. We also describe the application of shock-compression data for porous media. 

Shock-wave data have seen most applications in the measurement of density at high pressure. Other properties of compressed condensed materials whose measurements are discussed in this chapter include sound speed and temperature. Review articles by Grady (1977), Yakushev (1978), Davison and Graham (1979), Murri et al. (1974), Al tshuler (1965), and Miller and Ahrens (1991) summarize experimental techniques for measuring dynamic yielding. 

We assume that in (4.38) and (4.39), all velocities are measured with respect to the same coordinate system (at rest in the laboratory) and the particle velocity is normal to the shock front. When a plane shock wave propagates from one material into another the pressure (stress) and particle velocity across the interface are continuous. Therefore, the pressure-particle velocity plane representation proves a convenient framework from which to describe the plane Impact of a gun- or explosive-accelerated flyer plate with a sample target. Also of importance (and discussed below) is the interaction of plane shock waves with a free surface or higher- or lower-impedance media. 

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