22. Sphere Impact Induced Damage in Ceramics: III. Analysis

  1. Jeffrey J. Swab
  1. J. C. LaSalvia,
  2. M. J. Normandia,
  3. D. E. MacKenzie and
  4. H. T. Miller

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291276.ch22

Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7

Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7

How to Cite

LaSalvia, J. C., Normandia, M. J., MacKenzie, D. E. and Miller, H. T. (2008) Sphere Impact Induced Damage in Ceramics: III. Analysis, in Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7 (ed J. J. Swab), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291276.ch22

Author Information

  1. U. S. Army Research Laboratory—Aberdeen Proving Ground AMSRD-ARL-WM-MD Aberdeen, MD 21005–5069

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982374

Online ISBN: 9780470291276

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Keywords:

  • ceramic;
  • tungsten carbide;
  • spheres;
  • impact stress;
  • bending strength

Summary

In parts I and II of this study, the impact surface and sub-surface damage generated in four commercially-available hot-pressed armor-grade ceramics as the result of high-velocity impact with Tungsten Carbide spheres was presented. In this paper, a preliminary mechanical analysis is presented. The ceramic response is assumed to be elastic, perfectly-plastic; hence, the dependence of compressive strength on hydrostatic pressure is largely ignored. Based upon this assumption, the impact response of the ceramic can be divided into three regimes: (I) Elastic; (II) Elastic-Plastic; and (III) Fully-Plastic. These three regimes are represented by the following ranges for the mean impact stress pm: (I)pm/Y ≤ 1.1; (II) 1.1 ≤pm/Y ≤ 3; and (III) pm/Y = 3, where Y is the compressive “yield” strength. The analysis considers regimes (I) and (II) only, and examines the following issues: (1) Quasi-Static Impact; (2) Critical Velocities for the Onset of Plasticity and Full-Plasticity; and (3) Impact Stress and Contact Diameter. The analysis for impact stress and contact diameter is made with respect to Silicon Carbide.