$\Delta x$	The displacement of crosshead;
${\mathrm{L}}_1$	The length of steel from the fixed end to the center of the joint;
${\mathrm{L}}_2$	The length of Al from moving end to the center of the joint;
${\mathrm{L}}_{12}$	The length of steel from moving end to the center of the joint when the displacement of the crosshead is $\Delta x$;
${\mathrm{L}}_{22}$	The length of Al from moving end to the center of the joint when the displacement of the crosshead is $\Delta x$;
${{\mathrm{L}}^{\prime }}_1$	The length of steel from the fixed end to the left overlap end;
${{\mathrm{L}}^{\prime }}_2$	The length of Al from moving end to the right overlap end;
${{\mathrm{L}}^{\prime }}_{12}$	The length of steel from the fixed end to the left overlap end when the displacement of the crosshead is $\Delta x$;
${{\mathrm{L}}^{\prime }}_{22}$	The length of Al from the fixed end to the left overlap end when the displacement of the crosshead is $\Delta x$;
${\mathrm{t}}_1$	The thickness of steel;
${\mathrm{t}}_2$	The thickness of Al;
$\mathrm{d}$	The overlap distance;
${\mathrm{F}}_0$	The clamping force before loading;
$\mathrm{F}$	The force applied to pull the as-received joint at a specific displacement of $\Delta x$;
${\mathrm{F}}^{\prime }$	The force applied to pull the corroded joint at a specific displacement of $\Delta x$;
${\mathrm{M}}_1$	The bending moment of steel;
${\mathrm{M}}_2$	The bending moment of Al;
$\mathrm{\theta }$	The rotation angle of material;
${\mathrm{A}}_{\mathrm{steel}}$	The cross-section area of steel;
${\mathrm{A}}_{\mathrm{Al}}$	The cross-section area of Al.