Figure 8.

Asymmetric bidirectional model using FEM: strain in both x-axis and z-axis versus their own length with (a) $L_x\ne L_z$ and $D_x=D_z$; (b) $L_x=L_z$ and $D_x\ne D_z$; and (c) $L_x\ne L_z$ and $D_x\ne D_z$, where numerical image is shown in (d).