Speckle photography during dynamic impact of an energetic material using laser-induced fluorescence

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.365876· OSTI ID:526866

Asay, B W; Laabs, G W; Henson, B F; Funk, D J ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Laser and white light speckle photography have been used to observe surface displacement in a number of materials and over a varied range of strain rates. However, each suffers from limitations. We have developed a novel application of speckle photography in very difficult environments by using laser-induced fluorescence to generate the speckle pattern. This permits confinement of the free surface without undue degradation of the correlation upon which speckle methods are based. We have applied this method to measure the surface displacement of a reactive material during dynamic deformation at moderate strain rates. Conventional methods were tried but were unsuccessful, necessitating a novel approach. To the best of our knowledge, neither high-speed laser nor white light speckle photography has been performed using energetic materials. These measurements are very difficult because of the low material strength (yield strength {approximately}8{endash}80 MPa), and because significant out-of-plane motion and surface disruption occur during fracture, and early during the deformation process. We report results from experiments in which these major problems have been overcome. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 526866
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
DEFORMATION
FLUORESCENCE
FRACTURES
IMPACT SHOCK
MATERIALS TESTING
PHOTOGRAPHY
PHOTOLUMINESCENCE
STRAINS