${\mathrm{F}}_{\mathrm{d}}$	The drilling thrust force
${\mathrm{P}}_{\mathrm{u}}$ and ${\mathrm{P}}_{\mathrm{d}}$	The pressures applied on the clamping areas of upper side and lower side
${\mathrm{R}}_{\mathrm{u}1}$, ${\mathrm{R}}_{\mathrm{u}2}$, ${\mathrm{R}}_{\mathrm{d}1}$, and ${\mathrm{R}}_{\mathrm{d}2}$	The inner radius and outer radius of the upper and lower presser feet
${\mathrm{F}}_1$	The upper clamping force at circle with radius ${\mathrm{R}}_{\mathrm{u}}$
${\mathrm{F}}_2$	The lower clamping force at circle with radius ${\mathrm{R}}_{\mathrm{d}}$
${\mathsf{\mu }}_0$	The initial gap
$\mathsf{\mu }$	The interlayer gap
a	The length of the sheet;
b	The width of the sheet
h	The thickness of the sheet
$\mathsf{\omega }\left(\mathrm{O}\to \mathrm{r}\right)$	The deflection at the circle of radius $\mathrm{r}$ caused by unit force at drilling center
$\mathsf{\omega }\left({\mathrm{R}}_{\mathrm{u}}\to \mathrm{r}\right)$	The deflection at the circle of radius $\mathrm{r}$ caused by unit force at upper clamping area
$\mathsf{\omega }\left({\mathrm{R}}_{\mathrm{d}}\to \mathrm{r}\right)$	The deflection at the circle of radius $\mathrm{r}$ caused by unit force at lower clamping area
${\mathsf{\omega }}_1\left(\mathrm{r}\right)$	The deflection at the circle of radius $\mathrm{r}$ of upper plate
${\mathsf{\omega }}_{2\mathrm{d}}\left(\mathrm{r}\right)$	The deflection of the plate caused by the thrust force
${\mathsf{\omega }}_{2\mathrm{c}}\left(\mathrm{r}\right)$	The deflection of the lower plate caused by the lower clamping force
$∆\mathsf{\omega }\left(\mathrm{r}\right)$	The interlayer gap
${\mathsf{\omega }}_{\mathrm{u}}\left(\mathrm{r}\right)$	The deformation of the upper plate
${\mathsf{\omega }}_{\mathrm{d}}\left(\mathrm{r}\right)$	The deformation of the lower plate
$\mathsf{\omega }$	The deflection of the rectangular thin plate
$\mathrm{P}\left(\mathrm{x},\mathrm{y}\right)$	A point on the plate
${\mathrm{P}}_0\left({\mathrm{x}}_0,{\mathrm{y}}_0\right)$	The position of the drilling thrust force applied at the lower plate
${\mathrm{P}}_1\left({\mathrm{x}}_1,{\mathrm{y}}_1\right)$ and ${\mathrm{P}}_2\left({\mathrm{x}}_2,{\mathrm{y}}_2\right)$	The positions of the upper and lower clamping forces applied on the plates