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Impact and Blast Resistance of Sandwich Plates

  • George J. DvorakEmail author
  • Yehia A. Bahei-El-Din
  • Alexander P. Suvorov

Abstract

Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10−4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.

Keywords

Energy Release Rate Sandwich Plate Face Sheet Strain Energy Release Rate Blast Load 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgment

The authors gratefully acknowledge sustained support provided to us by the Office of Naval Research and Rensselaer Polytechnic Institute for more than 20 years. Dr. Yapa D.S. Rajapakse served as program monitor.

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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • George J. Dvorak
    • 1
    Email author
  • Yehia A. Bahei-El-Din
    • 2
  • Alexander P. Suvorov
    • 3
  1. 1.Northwestern UniversityEvanstonUSA
  2. 2.Center for Advanced MaterialsThe British University in EgyptEl Shorouk CityEgypt
  3. 3.McGill UniversityMontrealCanada

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