For an axial member, the relationship between its internal force and its deformation is given by:

$\mathrm{\delta }=\frac{\mathrm{FL}}{\mathrm{AE}}$

where
$\mathrm{\delta }$ = deformation,
$\mathrm{F}$ = internal force,
$\mathrm{L}$ = member length,
$\mathrm{A}$ = cross-sectional area, and
$\mathrm{E}$ = elastic modulus.