Micromechanical analysis of electro-elastic response of polymer composites reinforced with fuzzy fiber containing CNTs

In this paper the electromechanical behavior of fuzzy fiber reinforcement hybrid composites containing carbon nanotubes (CNTs) is investigated. A unit cell micromechanical model and electromechanical coupled constitutive equations are used to obtain the elastic and electrical coefficients of the hybrid composites. This hybrid composite is made up of piezoelectric fiber and CNT as reinforcement and polymer matrix. The piezoelectric fibers are coated with radially aligned CNTs. An interphase region is considered due to the interaction between CNT and matrix. The effect of volume fraction and size of CNT on the overall hybrid composite properties is investigated. These effects are remarkable in the transverse direction due to the aligned CNTs in the fiber radial direction. Considering PZT-7A as reinforcement piezoelectric fiber, study of its mechanical strength compared to PZT-5A was implemented in order to make a better composite. By comparing the proposed model with another micromechanical model, the validation of the proposed model is studied. Generally, a good agreement is observed between the results of these two models. The results also reveal that for the improved transverse electromechanical properties, using a CNT with a lower diameter is suggested.