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Characterization and modeling of specific strain gradient modulus of epoxy

Published online by Cambridge University Press:  31 January 2011

D. C. C. Lam  and
A. C. M. Chong
D. C. C. Lam
Affiliation:
Department of Mechanical Engineering, The Hong Kong University of Science and Technology Kowloon, Hong Kong
A. C. M. Chong
Affiliation:
Department of Mechanical Engineering, The Hong Kong University of Science and Technology Kowloon, Hong Kong
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Abstract

Microscale sensing and actuating components are prevalent in microelectromechanical systems. Deformations of microscale components are dependent not only on the strains in the body, but also on the strain gradients. The contribution of strain gradients to plastic hardening is characterized by the specific strain gradient modulus of the material. The specific strain gradient modulus has been predicted to vary with the plastic strain. The moduli of plastically prestrained epoxy specimens were experimentally characterized in this investigation using nanoindentation. Prestraining induced softening and an energy model are developed to separate the effect of prestrain softening from the effect of strain gradient. The results indicated that the contribution of strain gradient to hardening was initially large but diminished with increased plastic deformation. A model was developed for power law material and was shown to compare well with the experimental results.

Type
Articles
Information
Journal of Materials Research , Volume 16 , Issue 2 , February 2001 , pp. 558 - 563
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1.Fleck, N.A. and Hutchinson, J.W., Adv. in App. Mech. 33, 295 (1996).CrossRefGoogle Scholar
2.Nix, W.D. and Gao, H., J. Mech. Phys. Solids 46, 411 (1998).CrossRefGoogle Scholar
3.Fleck, N.A., Muller, G.M., Ashby, M.F., and Huchinson, J.W., Acta Metall. Mater. 42, 475 (1994).CrossRefGoogle Scholar
4.Stolken, J.S. and Evans, A.G., Acta Mater. 46, 5109 (1998).CrossRefGoogle Scholar
5.Gao, H., Huang, Y., Nix, W.D., and Hutchinson, J.W., J. Mech. Phys. Solids 47, 1239 (1999).CrossRefGoogle Scholar
6.Lam, D.C.C. and Chong, A.C.M., J. Mater. Res. 14, 3784 (1999).CrossRefGoogle Scholar
7.Chong, A.C.M. and Lam, D.C.C., J. Mater. Res. 14, 4103 (1999).CrossRefGoogle Scholar
8.Chanda, M. and Roy, S.K., Plastic Technology Handbook (M. Dekker, New York, 1993), pp. 369–570.Google Scholar
9.Mayr, A.E., Cook, W.D., and Edward, G.H., Polymer 39, 3719 (1998).CrossRefGoogle Scholar
10.G’Sell, C., Hiver, J.M., Dahoun, A., and Souahi, A., J. Mater. Sci. 27, 5031 (1992).CrossRefGoogle Scholar
11.Chaki, T.K. and Li, J.C.M., J. Appl. Phys. 56, 2392 (1984).CrossRefGoogle Scholar
12.Sneddon, I.N., Int. J. Engng. Sci. 3, 47 (1965).CrossRefGoogle Scholar
13.Oliver, W.C. and Pharr, G.M., J. Mater. Res. 7, 1564 (1992).CrossRefGoogle Scholar
14.Johnson, K.L., Contact Mechanics (Cambridge University Press, 1985).CrossRefGoogle Scholar
15.Lam, D.C.C. and Chong, A.C.M., Mater. Sci. Eng. A. 281, 156 (2000).CrossRefGoogle Scholar