In the development of special explosion-proof chambers that must meet strict requirements for strength reliability, an important issue is the choice of the material of the load-bearing shell subjected to pulsed (dynamic and shock-wave) loads. As a rule, these structures are made from industrial low-alloy steel pipes of various standard sizes. This always raises the question of choosing the steel grade, especially at the stage of design-basis justification of their explosion resistance, since the dynamic strength characteristics of the pipe material are generally unknown. This paper is the first to present the results of analysis of the static, dynamic, and shock-wave compressive and tensile strengths of 17G1S, 09G2S, 10G2FBYu, and K60 strength class pipe steels. In addition, comparative data are given on the explosion resistance of pipes of 09G2S and 10G2FBYu steels at a strain rate of (2-5)· 10^2 s ^-1 .

An Erratum to this paper has been published: https://doi.org/10.1134/S106377612230001X

Large explosion-proof chambers are manufactured using cylindrical shells made of sheet metal by rolling and welding with addition of longitudinal and circumferential seams. In this case, one should make a choice of steel with increased strength or ductility. In this regard, this work presents the results of a study of the reaction of such 09G2S and 10KhSND steel shells to dynamic loading.

The results of experimental studies of the shock-induced particle ejection (“dusting”) from a free rough ( R z = 20) surface of lead and copper samples into an evacuated medium are presented. The experimental methods were based on different physical principles. To determine the size of particles by shadow laser-optical imaging more efficiently, a narrow strip was isolated in the center of the free surface of a sample from which an optically transparent stream of particles was ejected. The rest of the surface, substantially larger in size, ejected particles, parameters of which were reliably recorded using optical heterodyne interferometry detection, radiographic imaging, and piezoelectric techniques. This made it possible to obtain more reliable data on the particle size distribution, the velocity of the front of a particle flux, and the density (weight) distribution of the flow in the direction of its motion, necessary to refine the existing models and create more reliable models to describe the phenomenon. Using lead and copper samples, the material of which melts or does not melt under shock wave loading in selected close conditions (amplitude of the shock wave and roughness of the free surface), made it possible to clearly demonstrate the effect of melting on the qualitative pattern and quantitative characteristics of the shock-induced dusting process.

For about 15 years, studies of fast gas-dynamic processes have been conducted at the Logunov Institute of Experimental Physics (VNIIEF) of the Russian Federal Nuclear Center using the proton radiography system developed jointly with the Logunov Institute of High Energy Physics on the basis of a U-70 accelerator. The main advantages of flash proton radiography over widely used flash x-ray radiography are high spatial resolution, multiframe mode, transmission capability, dynamic range of recording, etc. In recent years, effort has continued to extend the capabilities of the proton radiography system by increasing the total time and recording field and supplementing it with additional diagnostic techniques and new explosion-proof chambers. This paper presents the results of studies that illustrate these capabilities.

We report results from an experiment on Pb that we explosively shock loaded to PSL≈32\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P_{SL} \approx 32$$\end{document}- and 43-GPa, in a single experiment. These PSL\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P_{SL}$$\end{document} caused the Pb sample to isentropically release to either a liquid or mixed solid–liquid phase post-shock. The post-shock sample damage and dynamics were diagnosed with proton radiography, which gave quantitative damage data within three distinct regions. The first region is the particle (ejecta) cloud, where we observed that total areal mass ejected from the shocked Pb surface is in-dependent of the peak PSL\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P_{SL}$$\end{document} for unsupported (Taylor wave) shockwave loading. The second region, which exhibits spall and cavitation, distends and disperses as the shocked coupon self-similarly expands subsequent to the shockwave impulse and the release into tension. The third region includes undamaged, full density Pb sample. We report quantitative observations from all three regions, and we used the data to evaluate and validate damage and ejecta models, which satisfactorily describe the observed experimental dynamics.

We report experimental results on studies of the interactions between various gases and the mass ejected from a shock accelerated surface. While such studies have been conducted in the past, data on such dynamic gas-ejecta interactions are incomplete. Therefore, along these lines, in the present work new comparative results are given concerning mass ejection from free surfaces of lead interfaced with vacuum or gas. The comparisons are made for the ejecta mass as a function of the surface roughness, the peak shockwave loading stress (amplitude) \(P_S\), and the release phase (state) of the post-shock metal.

We report results from an experiment on Pb that we explosively shock loaded to \(P_{SL} \approx 32\)- and 43-GPa, in a single experiment. These \(P_{SL}\) caused the Pb sample to isentropically release to either a liquid or mixed solid–liquid phase post-shock. The post-shock sample damage and dynamics were diagnosed with proton radiography, which gave quantitative damage data within three distinct regions. The first region is the particle (ejecta) cloud, where we observed that total areal mass ejected from the shocked Pb surface is in-dependent of the peak \(P_{SL}\) for unsupported (Taylor wave) shockwave loading. The second region, which exhibits spall and cavitation, distends and disperses as the shocked coupon self-similarly expands subsequent to the shockwave impulse and the release into tension. The third region includes undamaged, full density Pb sample. We report quantitative observations from all three regions, and we used the data to evaluate and validate damage and ejecta models, which satisfactorily describe the observed experimental dynamics.

We report results from an experiment on Pb that we explosively shock loaded to P_SL≈ 32 - and 43-GPa, in a single experiment. These P_SL caused the Pb sample to isentropically release to either a liquid or mixed solid–liquid phase post-shock. The post-shock sample damage and dynamics were diagnosed with proton radiography, which gave quantitative damage data within three distinct regions. The first region is the particle (ejecta) cloud, where we observed that total areal mass ejected from the shocked Pb surface is in-dependent of the peak P_SL for unsupported (Taylor wave) shockwave loading. The second region, which exhibits spall and cavitation, distends and disperses as the shocked coupon self-similarly expands subsequent to the shockwave impulse and the release into tension. The third region includes undamaged, full density Pb sample. We report quantitative observations from all three regions, and we used the data to evaluate and validate damage and ejecta models, which satisfactorily describe the observed experimental dynamics.

The presence and behavior of a gas–metal interfacial layer at the free surface of shock-wave driven flying vehicles in gases of various compositions and densities has not been sufficiently studied so far. We present new comparative data on “dusting” from the free surface of lead into vacuum and gas as dependent on the surface roughness, pressure amplitude at the shock-wave front, and phase state of the material. Methods of estimating the mass flux of ejected particles in the presence of a gas medium at the free metal surface are proposed.

In view of the possible effect of contamination of a plasma by metal particles on the operation of a number of facilities or on the detection of the motion of liners by Doppler methods, a particular attention has been recently focused on the problem of the ejection of particles from the shock-loaded free surface of a sample or on the “dusting” problem. Most information concerns the dusting source associated with the roughness of the surface, manufacturing technology, and the defectiveness and aging of a material. Factors affecting this process such as the profile and amplitude of the pressure on the front of the shock wave arriving at the free surface of the sample, the presence of the gas in front of the free surface, and the pressure in this gas are less studied.

Within the framework of the scientific trend that was developed at the Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, explosion-protecting chambers (EPCs) of different types with working volumes ranging from ∼10 −3 to ∼10 m 3 were developed and constructed. They are able to hermetically localize explosion products from explosive charges of units of grams to tens of kilograms (in the trinitrotoluene equivalent (TNTE)). Scientific and engineering approaches to designing the EPC structures, which are based on experimental methods and numerical simulation, are presented. Examples of developed chambers that are used in studies of a number of hydrodynamic processes are given.

This work presents the results of experiments on the compression of a spherical copper shell loaded by the detonation of a plastic explosive layer. A U-70 accelerator is used for radiographic recording of the convergence of the shell to the center, and metallographic analysis of the copper shell preserved after the experiment is performed. The results of multiframe proton radiography of the convergence of the inner boundary of the copper shell to the center are compared with the results of numerical simulations.

The possibilities of measuring complex Pylenie, which is intended for studying the parameters of the particles ejected from the free surface of a shock-loaded material and was created at the Institute of Experimental Gas Dynamics and Detonation Physics RFNC-VNIIEF, are demonstrated. The operation of the complex is based on the following three methods, which are based on different physical principles and supplement each other: laser-optical method (macro- and microfilming), pulsed X-ray method, and piezoelectric pressure sensors. This complex is used to study the ejection of particles from the free surface of lead samples when a shock wave with a pressure of 7, 16, and 23 GPa at its front reaches this surface. The effect of the surface roughness and the pressure amplitude at the shock wave front on the quantitative characteristics of the process is shown. The calculation-theoretical simulation is performed by two-dimensional numerical calculations of gasdynamic flows, and the calculation results are used to estimate the “ejecta” characteristics in terms of the developed phenomenological model of the process.