TY - JOUR
T1 - The influence of inclusion shape on the overall elastoplastic behavior of a two-phase isotropic composite
AU - Qiu, Y. P.
AU - Weng, G. J.
N1 - Funding Information: Aeknawledgement-This work was supported by the National Science Foundation, Solid and GeoMechanics Program, under Grant MSM 86-14151.
PY - 1991
Y1 - 1991
N2 - A mean-field, approximate theory is developed for the determination of the overall stress-strain relation of a two-phase composite, consisting of randomly oriented elastic, spheroidal inclusions and a ductile matrix. The theory is intended for a low-volume concentration of inclusions. It is versatile enough to provide results under any proportionally increasing combined stresses, and yet simple enough to require no iterations. To preserve the virtue of simplicity, the simpler deformation theory is used over the incremental one. More so than the elastic behavior, the elastoplastic response of the composite is found to be extremely sensitive to the inclusion shape, with the discs providing the most remarkable reinforcement. Explicit results of the overall secant moduli are established for the three extreme inclusion shapes of disc, needle (fiber) and sphere. An interesting consequence of this analysis is that while both the particle and fiber-reinforced composites become plastically compressible, the disc-reinforced composite as the ductile matrix itself - remains plastically incompressible. When applied to a silicon-carbide /aluminum system, the theory indicates that within the aspect ratio α < 10, the prolate and oblate inclusions with inversed aspect ratios (i.e. α and 1α) have almost the same effect on the flow stress of the composite, but beyond this the discoriented inclusions begin to show a more superior influence. The theory also compares reasonably with the experimental data when the carbides exist in the form of randomly oriented platelets, with α = 1 4.
AB - A mean-field, approximate theory is developed for the determination of the overall stress-strain relation of a two-phase composite, consisting of randomly oriented elastic, spheroidal inclusions and a ductile matrix. The theory is intended for a low-volume concentration of inclusions. It is versatile enough to provide results under any proportionally increasing combined stresses, and yet simple enough to require no iterations. To preserve the virtue of simplicity, the simpler deformation theory is used over the incremental one. More so than the elastic behavior, the elastoplastic response of the composite is found to be extremely sensitive to the inclusion shape, with the discs providing the most remarkable reinforcement. Explicit results of the overall secant moduli are established for the three extreme inclusion shapes of disc, needle (fiber) and sphere. An interesting consequence of this analysis is that while both the particle and fiber-reinforced composites become plastically compressible, the disc-reinforced composite as the ductile matrix itself - remains plastically incompressible. When applied to a silicon-carbide /aluminum system, the theory indicates that within the aspect ratio α < 10, the prolate and oblate inclusions with inversed aspect ratios (i.e. α and 1α) have almost the same effect on the flow stress of the composite, but beyond this the discoriented inclusions begin to show a more superior influence. The theory also compares reasonably with the experimental data when the carbides exist in the form of randomly oriented platelets, with α = 1 4.
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U2 - https://doi.org/10.1016/0020-7683(91)90076-R
DO - https://doi.org/10.1016/0020-7683(91)90076-R
M3 - Article
VL - 27
SP - 1537
EP - 1550
JO - International Journal of Solids and Structures
JF - International Journal of Solids and Structures
SN - 0020-7683
IS - 12
ER -