Propagation of steady shock waves in polymethyl methacrylate
TL;DR: The particle-velocity histories associated with the compression waves produced by the planar impact of polymethyl methacrylate plates were observed by means of laser interferometry as mentioned in this paper.
Abstract: The particle-velocity histories associated with the compression waves produced by the planar impact of polymethyl methacrylate plates were observed by means of laser interferometry The impact velocity and the thickness of material through which the wave passed were varied from 006 to 064 mm μsec and from 6 to 37 mm respectively Over this range of impact velocities, the observations disclosed a shock followed by a smooth transition to the maximum particle-velocity; the speed and magnitude of the shock varied non-linearly with the impact stress For impact velocities below 03 mm μsec , the wave was steady A steady-wave analysis based on finite linear viscoelasticity theory has been shown to be in good agreement with the experimental observations
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TL;DR: In this paper, a review of the status of investigations concerning the response of solids to shock compression is presented, focusing on physical interpretation of observations peculiar to the shock environment and the relationships among observations in the various areas of investigation.
398 citations
TL;DR: In this paper, the authors applied laser interferometry to measure particle velocity history at the interface between a shocked specimen and a transparent window material, and demonstrated that the loss of fringe contrast can be used to provide time-resolved measurements of the spatial variations in particle velocity.
Abstract: Methods of applying laser interferometry to measure particle velocity history at the interface between a shocked specimen and a transparent window material are discussed Particular emphasis is given to diffusely reflecting interface surfaces, to shock‐induced light polarization shifts which can occur in the window material, and to a transient loss of fringe contrast which occurs whenever the reflecting surface velocity is spattially nonuniform It is shown that the loss of finge contrast can be used to provide time‐resolved measurements of the spatial variations in particle velocity
115 citations
TL;DR: In this paper, the elastic-plastic shock response was measured using laser interferometry, and elastic Hugoniots were obtained from the measurements, which indicated that the inelastic deformation mechanisms may vary with orientation.
Abstract: The explosive molecular crystal cyclotetramethylene tetranitramine was studied in three orientations in a set of plate impact experiments; the orientations studied were {110}, {011}, and {010} in P21/n space group. The elastic–plastic shock response was measured using laser interferometry. The measured particle velocity profiles showed elastic precursor decay typical of a stress relaxing material. There is anisotropy in elastic shock strength and decay. The amount of precursor decay with propagation distance and stress relaxation behind the elastic shock varied among the orientations. The {010} orientation had larger elastic precursors than did the other two orientations; the {010} crystal does not have the regular plastic deformation mechanisms available to it. Elastic Hugoniots were obtained from the measurements. The inelastic deformation mechanisms may vary with orientation.
111 citations
TL;DR: In this paper, the nucleation and growth functions for incipient fracture damage were deduced from the observed damage and from measured and computed stress histories, allowing quantitative prediction of the shock damage produced by arbitrary stress histories in polycarbonate.
Abstract: Flat‐plate impact experiments were performed on polycarbonate specimens to produce various levels of fracture damage. Nucleation and growth functions for incipient shock damage were deduced from the observed damage and from measured and computed stress histories. These functions allow quantitative prediction of the shock damage produced by arbitrary stress histories in polycarbonate.
102 citations
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TL;DR: One-dimensional acceleration waves and higher order waves propagating in general nonlinear Maxwellian materials with fading memory were studied in this paper, where they were shown to have fading memory.
Abstract: One-dimensional acceleration waves and higher order waves propagating in general nonlinear Maxwellian materials with fading memory
182 citations
TL;DR: In this paper, a new technique is described for measuring the position history of the free surface of an impacted specimen, and measurements can be made to 0.025 μ accuracy at free surface velocities up to 1 mm/μsec.
Abstract: A new technique is described for measuring the position history of the free surface of an impacted specimen. Measurements can be made to 0.025 μ accuracy at free surface velocities up to 0.1 mm/μsec. Problems and possible solutions for monitoring higher velocities are indicated.
175 citations
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