Theory of Plasticity for a Class of Inclusion and Fiber-Reinforced Composites
Based on the theoretical framework recently established by Tandon and Weng (1988), a multiaxial theory of plasticity is developed for a class of composites containing unidirectionally aligned spheroidal inclusions. The aspect ratio of inclusions may range from that of a thin disk all the way to that of a continuous fiber, and its influence on the transversely isotropic elastoplastic behavior of the composite is investigated. Under a combined stress the secant moduli of the composite and the average stress concentration factors of the matrix are derived. It is shown that the yield condition of the composite generally depends on the hydrostatic pressure, contributing most significantly for the disk and fiber-reinforced cases. Both the initial yield stress and the work-hardening modulus of the anisotropic composite are also seen to be strongly influenced by the shape of inclusions; the disks are found to be most effective in the transverse plane but the fibers are so along the axial direction. Finally, a rather detailed account on the elastoplastic behavior of fiber-reinforced composites is given, and a comparison of the stress-strain curve with experiment is also demonstrated.
KeywordsBoron Hexagonal Posite Verse Prolate
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- Accorsi, M. L. and Nemat-Nasser, S. (1986), Bounds on the overall elastic and instan-taneous elastoplastic moduli of periodic composites, Mech. Materials, 5, 209–220.Google Scholar
- Dvorak, G. J. and Bahei-El-Din, Y. A. (1987), A bimodal plasticity theory of fibrous composite materials, Acta Mech, 69, 219–241.Google Scholar
- Dvorak, G. J., Bahei-El-Din, Y. A., Macheret, Y., and Liu, C. H. (1988), An experimental study of elastic-plastic behavior of a fibrous boron-aluminum composite, J. Mech. Phys. Solids,36, 655–687.Google Scholar
- Eshelby, J. D. (1957), The determination of the elastic field of an ellipsoidal inclusion, and related problems, Proc. Roy. Soc. London, A241, 376–396.Google Scholar
- Luo, H. A. and Weng, G. J. (1989), On Eshelby’s S-tensor in a three-phase cylindrically concentric solid, and the elastic moduli of fiber reinforced composites, Mech. Materials,8 (in press).Google Scholar
- Mura, T. (1987),Micromechanics of Defects in Solids, 2nd ed., Martinus Nijhoff, Dordrecht. Pedersen, O. B. (1983), Thermoelasticity and plasticity of composites-I. Mean field theory,Acta Metallurgica, 13, 1795–1808.Google Scholar
- Teply, J. L. and Dvorak, G. J. (1988), Bounds on overall instantaneous properties of elastic-plastic composites, J. Mech. Phys. Solids,36, 29–58.Google Scholar
- Weng, G. J. (1988), Theoretical principles for the determination of two kinds of composite plasticity, in Mechanics of Composite Materials, edited by Dvorak, G. J. and Laws, N., AMD-Vol. 92, ASME, New York, pp. 193–208.Google Scholar