“…where u, v and w are the displacements of particle at (x, y, z) in the rod along x, y and z axes, respectively; ν 12 and ν 13 are the Poisson's ratios with respect to y and z axes, respectively; and r¨s T denotes the transposition of a matrix (or vector). The strain vector ε " rε x , ε y , ε z , γ yz , γ zx , γ xy s T and the electric field vector E " rE x , E y , E z s T can then be derived from the generalized strain-displacement relations …”