Numerical Evaluation of Stress Intensity Factors in Functionally Graded CNTRC Plates

Abstract

The numerical evaluation of stress intensity factors (SIFs) is presented for functionally graded CNT-reinforced composite (FG-CNTRC) plate. The 3-D linear elasticity of cracked orthotropic plate is formulated in terms of 2-D FEM and the (1,1,0) hierarchic model which is sort of the first-order shear deformation theory. Meanwhile, a 2-D thickness-wise plane within FG-CNTRC plate is taken for the numerical evaluation of SIFs. The thickness-wise mixed-mode SIFs are evaluated from the interaction integral by introducing the 2-D complex-valued orthotropic crack-tip singular fields. The numerical evaluation method is validated by comparing with the other reference methods, with the maximum relative difference equal to 31.43%. Moreover, the SIF characteristics of FG-CNTRC are numerically investigated. It is revealed that the thickness-wise volume fraction distribution of CNTs significantly influences the magnitude and variation of SIFs. However, the volume fraction magnitude of CNTs does not show an apparent consistent effect on the both items of SIFs.