Advertisement

Journal of Materials Engineering and Performance

, Volume 12, Issue 5, pp 561–568 | Cite as

Ball indentation analysis of a tough polymer sheet

  • Malik M. Nazeer
  • M. Afzal Khan
  • A. Naeem
  • A. ul Haq
Processing

Abstract

The ball indentation process of tough polymer sheet clamped at its periphery has various particular response characteristics. These characteristics of the polymer sheet have been discussed in comparison to the ductile metal sheet undergoing a similar indentation process. The ball indentation process of polymer sheet is also mathematically analyzed to evaluate fracture toughness and distribution of the energy used. This analysis is useful for designers to foresee the pre- and post-peak load response and possible aftermath. The information and results presented may be useful to meet some particular design and utility demands. Data for a number of tests was recorded and analyzed and it was observed that at a particular load and corresponding displacement, fracture first begins within the dimple. The fracture toughness and energy used were calculated using a mathematical model developed for computations. The energy-based equations of Rigid-Plastic Fracture Mechanics have been used for computational model for steel balls indentation, perforation, and fracture propagation. The dependence of various parameters on the indenting ball diameter and bearing of the anisotropy due to sheet extrusion is elaborated.

Keywords

elasto-plastic flow fracture propagation fracture toughness perforation polymer indentation characteristics 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    T. Wierzbicki and N. Jones: Fracture, John Wiley, New York, NY, 1988, pp. 107–32.Google Scholar
  2. 2.
    F.A. McClintock: “A Criterion for Ductile Fracture by the Growth of Holes,” J. Appl. Mech., 1968, 35, pp. 363–71.Google Scholar
  3. 3.
    M.A. Khan, M.M. Nazeer, A. Naeem, A. ul Haq, and A.G. Atkins: “Computer Modeling of Elasto-Plastic Fracture Mechanics of Ball Indentation in Ductile Aluminum Sheet” in Proc. EUROMAT 95, Padua/Venice, Italy, 1995, pp. 491–94.Google Scholar
  4. 4.
    A.G. Atkins and Y.W. Mai: Elastic and Plastic Fracture, Ellis Harwood, John Wiley, UK, 1988, pp. 574–80.Google Scholar
  5. 5.
    A.G. Atkins: “On Cropping and Related Processes,” Int. J. Mech. Sci., 1980, 22, pp. 215–31.CrossRefGoogle Scholar
  6. 6.
    K. Vijay and G.E. Stokes: “Residual Stresses and Dimensional Stability in Injection Molded Thermoplastic Parts” in Proc. Symposium on Long Term Performance Issue in Polymer Chemistry and Physics, Corporate Research & Development, Schenectady, NY, 28 Nov.-1 Dec., 1995.Google Scholar
  7. 7.
    M.M. Nazeer, M.A. Khan, A. Naeem, and A. ul Haq: “Analysis of Conical Tool Perforation of Ductile Meatl Sheets,” Int. J. Mech. Sci., 2000, 42, pp. 1391–403.CrossRefGoogle Scholar
  8. 8.
    M.M. Nazeer, M.A. Khan, A. Naeem, A. ul Haq, and A.G. Atkins: “Mathematical Analysis of Sharp Tool Indented Aluminium Sheet Curvature” in Proc. Int. Conf. on Pure and Applied Mathematics, ICPAM 95, Bahrain, 1995.Google Scholar
  9. 9.
    A.G. Atkins, M.A. Khan, and J.M. Liu: “Necking and Radial Crack Around Perforation in the Sheet at Normal Incidence,” Int. J. Impact Eng., 1998, 21(7), pp. 521–39.CrossRefGoogle Scholar
  10. 10.
    M.M. Nazeer, M.A. Khan, A. Naeem, and A. ul Haq: “Response of Ductile Metal Sheet Parameters to the Cone Angle of Indenting Conical Tool,” Int. J. Mater. Perform., 2000.Google Scholar
  11. 11.
    R.W. Hertzberg: Deformation and Fracture Mechanics of Engineering Materials, John Wiley and Sons, New York, NY, 1976.Google Scholar
  12. 12.
    A.B. Strong: “Plastic Materials and Processing,” 2nd ed., Prentice Hall, NJ, 2000, pp. 244–86 and 640–748.Google Scholar
  13. 13.
    G.H. Ryder: “Strength of Material,” English Language Book Society and McMillan Press Ltd, London, UK, 1996, pp. 86–128.Google Scholar
  14. 14.
    S. Timoshenko: “Strength of Material—Part I Elementary,” Van Nostrand Reinhold, New York, NY, pp. 415–28.Google Scholar
  15. 15.
    S. Timoshenko: “Strength of Material—Part II Advanced Theory and Problems,” 3rd ed., CBS Publishers and Distributors, Delhi, India, 1986, p. 448.Google Scholar

Copyright information

© ASM International 2003

Authors and Affiliations

  • Malik M. Nazeer
    • 1
  • M. Afzal Khan
    • 1
  • A. Naeem
    • 1
  • A. ul Haq
    • 1
  1. 1.Dr. A.Q. Khan Research LaboratoriesRawalpindiPakistan

Personalised recommendations