The nonlinear lateral buckling response of perfect stocky beams in the
vicinity of the critical bifurcational state is discussed. Attention
is focused on the initial post-buckling response. This depends on the
nature of the critical branching point which is explored by using a no
nlinear (lateral) bending-curvature relationship. It is found that the
plane of loading (associated with the major moment of inertia) looses
its stability through a stable symmetric bifurcation point. Hence, th
e above beams are not sensitive to imperfections, exhibiting post-buck
ling strength. However, the post-buckling equilibrium path is quite sh
allow, so that the load-carrying capacity of such beams above the crit
ical state is rather limited. The analysis is supplemented by illustra
tive examples for I-beams for which the effect of various parameters o
n the initial postbuckling path is also discussed.