Elastoplastic behavior of the metal matrix nanocomposites containing carbon nanotubes: A micromechanics

The elastoplastic behavior of aluminum (Al) nanocomposites reinforced with aligned carbon nanotubes (CNTs) is characterized using a unit cell micromechanical model. The interphase zone caused by the chemical reaction between CNT and Al matrix is included in the analysis. To attain the elastoplastic stress–strain curve of the nanocomposites, the successive approximation method together with the von Mises yield criterion is employed. The effects of several important factors including the volume fraction and diameter of CNT, material properties, and size of interphase on the elastoplastic stress–strain curve of the nanocomposites during uniaxial tension are studied. The results indicate that the interphase characteristics significantly affect the elastoplastic behavior of the CNT-reinforced Al nanocomposites. It is also found that the yield stress of the nanocomposites rises with increasing CNT volume fraction or decreasing CNT diameter. Besides, the elastoplastic stress–strain curve of the CNT-reinforced Al nanocomposites is presented for multiaxial tension. The initial yield envelopes of the nanocomposites under longitudinal–transverse biaxial tension are provided too. Comparison between the elastic results of the present model with those of other available micromechanical analyses shows a very good agreement