Strain Rate Sensitivity of Epoxy Resin in Tensile and Shear Loading
Publication: Journal of Aerospace Engineering
Volume 20, Issue 2
Abstract
The mechanical response of E-862 and PR-520 resins is investigated in tensile and shear loadings. At both types of loading the resins are tested at strain rates of about , 2, and . In addition, dynamic shear modulus tests are carried out at various frequencies and temperatures, and tensile stress relaxation tests are conducted at room temperature. The results show that the toughened PR-520 resin can carry higher stresses than the untoughened E-862 resin. Strain rate has a significant effect on the response of both resins. In shear, both resins show a ductile response with maximum stress that is increasing with strain rate. In tension, a ductile response is observed at low strain rate , and brittle response is observed at the medium and high strain rates (2 and ). The hydrostatic component of the stress in the tensile tests causes premature failure in the E-862 resin. Localized deformation develops in the PR-520 resin when loaded in shear. An internal state variable constitutive model is proposed for modeling the response of the resins. The model includes a state variable that accounts for the effect of the hydrostatic component of the stress on the deformation.
Get full access to this article
View all available purchase options and get full access to this article.
References
Bodner, S. R. (2002). Unified plasticity for engineering applications, Kluwer Academic/Plenum, New York.
Bordonaro, C. M. (1995). “Rate dependent mechanical behavior of high strength plastics: Experiment and modeling.” Ph.D. thesis, Rensselaer Polytechnic Institute, Troy, New York.
Buckley, C. P., Harding, J., Hou, C., Ruiz, C., and Trojanowski, A. (2001). “Deformation of thermosetting resins at impact rates of strain. I: Experimental study.” J. Mech. Phys. Solids, 49, 1517–1538.
Chang, W. J., and Pan, J. (1997). “Effects of yield surface shape and round-off vertex on crack-tip fields for pressure-sensitive materials.” Int. J. Solids Struct., 34, 3291–3320.
Chen, W., and Zhou, B. (1998). “Constitutive behavior of Epon 828/T-403 at various strain rates.” Mech. Time-Depend. Mater., 2, 103–111.
Gilat, A. (2000). “Torsional Kolsky bar testing.” ASM metals handbook, Vol. 8, Mechanical Testing and Evaluation, American Society of Metals, Materials Park, Ohio, 505–515.
Gilat, A., and Krishna, K. (1977). “The effects of strain rate and thickness on the response of thin layers of solder loaded in pure shear.” ASME J. Electron. Packag., 19, 81–84.
Goldberg, R. K., Roberts, G. D., and Gilat, A. (2003). “Implementation of an associative flow rule including hydrostatic stress effects into the high strain rate deformation analysis of polymer matrix composites.” NASA/TM-2003-212382, National Aeronautics and Space Administration, Washington, D.C.
Hou, J. P., Ruiz, C., and Trojanowski, A. (2000). “Torsion tests of thermosetting resins at impact strain rate and under quasi-static loading.” Mater. Sci. Eng., A 283, 181,188.
Hsu, S.-Y., Vogler, T. J., and Kyriakides, S. (1999). “Inelastic behavior of an AS4/PEEK composite under combined transverse compression and shear. II: Modeling.” Int. J. Plast., 15, 807–836.
Khan, A. S., and Huang, S. (1995). Continuum theory of plasticity, Wiley, New York.
Kody, R. S., and Lesser, A. J. (1977). “Deformation and yield of epoxy networks in constrained states of stress.” J. Mater. Sci., 32, 5637–5643.
Kolsky, H. (1949). “An investigation of the mechanical properties of materials at very high rates of loading.” Proc. Phys. Soc. London, Sect. B, 62-B, 676–700.
Krempl, E., and Ho, K. (2000). “An overstress model for solid polymer deformation behavior applied to nylon 66, time dependent and nonlinear effects in polymers and composites.” ASTM STP 1357, R. A. Schapery and C. T. Sun, eds., ASTM, West Conshohocken, Pa. 118–137.
Li, F. Z., and Pan, J. (1990). “Plane-stress crack-tip fields for pressure-sensitive dilatant materials.” J. Appl. Mech., 57, 40–49.
Shah Khan, M. Z., Simpson, G., and Townsend, C. R. (2002). “A comparison of the mechanical properties in compression of two resin systems.” Mater. Lett., 52, 173–179.
Staab, G. H., and Gilat, A. (1995). “High strain rate response of angle-ply glass/epoxy laminate.” J. Compos. Mater., 29, 1308–1320.
Stouffer, D. C., and Dame, L. T. (1996). Inelastic deformation of metals, models, mechanical properties, and metallurgy, Wiley, New York.
Walley, S. M., Field, J. E., Pope, P. H., and Safford, N. A. (1989). “A study of the rapid deformation behaviour of a range of polymers.” Philos. Trans. R. Soc. London, Ser. A, 328(1597), 1–33.
Ward, I. M. (1983). Mechanical properties of solid polymers, Wiley, New York.
Wineman, A. S., and Rajagopal, K. R. (2000). Mechanical response of polymers, Cambridge University Press, New York.
Zhang, C., and Moore, I. D. (1997). “Nonlinear mechanical response of high density polyethylene. II: Uniaxial constitutive model.” Polym. Eng. Sci., 37, 414–420.
Information & Authors
Information
Published In
Journal of Aerospace Engineering
Volume 20 • Issue 2 • April 2007
Pages: 75 - 89
Copyright
© 2007 ASCE.
History
Received: Jul 1, 2005
Accepted: Mar 20, 2006
Published online: Apr 1, 2007
Published in print: Apr 2007
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.