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Applications: Impacted Plate

 
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   - make cut
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   - calculate stress
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Residual Stress
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download paper M. B. Prime, R. L. Martineau, "Mapping Residual Stresses After Foreign Object Damage Using The Contour Method," Materials Science Forum, Vols. 404-407, pp. 521-526, 2002.
download preprint R. L. Martineau, M. B. Prime, and T. Duffey, "Penetration of HSLA-100 Steel with Tungsten Carbide Spheres at Striking Velocities Between 0.8 and 2.5 km/sec," International Journal of Impact Engineering, 30(5), pp. 505-520, 2004.

Results: Residual Stresses After Foreign Object Damage (i.e. Impact/Penetration Event.) Over cross-section of plate

measured residual stresses

  • Impact left a region of very high compressive residual stress under the impact crater
  • High tensile stresses at edges of plate are from flame cutting specimen from larger plate, not from impact event
  • Plate still shows background quenching stresses that were there before impact


Specimen:
  • Same HSLA-100 steel as quench plate measurement
  • Impacted by tungsten carbide sphere traveling at 2.2 km/sec.
  • Figure shows plate already cut through one of several impact craters
Specimen showing surface cut through one  of the impact craters

Measurement Details

  • Cut in Mitsubishi FX-10 wire EDM with 150 µm (0.006") diameter brass wire.
  • Surface contour measured using MS Impact II CMM.
  • Stresses calculated by applying opposite of measured contour to FEM model
  • Images:
Measurement of surface contour
Measurement of surface contour in Coordinate Measuring Machine
Deformed finite element model
FEM Model used to calculate residual stress from measured data. Front surface (surface that was cut) is deformed into opposite shape of measured contour

 

 

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Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
contact: Mike Prime at prime@lanl.gov | Copyright & Disclaimer
U.S. patent 6,470,756 | Last Modified: September 5, 2007

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