The variational-asymptotic method was recently applied to create a beam theory for
a thin strip-beam with a width that varies linearly with respect to the axial
coordinate. For any arbitrary section, ratios of the cross-sectional stiffness coefficients
to their customary values for a uniform beam depend on the rate of taper. This is
because for a tapered beam the outward-directed normal to a lateral surface is
not perpendicular to the longitudinal axis. This changes the lateral-surface
boundary conditions for the cross-sectional analysis, in turn producing different
formulae for the cross-sectional elastic constants as well as for recovery of
stress, strain and displacement over a cross-section. The beam theory is
specialized for the linear case and solutions are compared with those from
plane-stress elasticity for stress, strain and displacement. The comparison
demonstrates that for beam theory to yield such excellent agreement with
elasticity theory, one must not only use cross-sectional elastic constants that are
corrected for taper but also the corrected recovery formulae, which are in
turn based on cross-sectional in- and out-of-plane warping corrected for
taper.