Abstract:
A finite element program, applicable to the pre-
and post-buckling behaviour of plates with imperfections,
is developed. Suitable incremental stiffness matrices
are generated for a plate element with four nodes and
twenty degrees of freedom.
Preliminary work, together with a prototype pro-
gram, is carried out on a simple strut in order to
compare various nonlinear solution techniques, both
incremental and iterative. Th6 plate program is veri-
fied by large deflection calculations for a square plate
under lateral pressure, and by comparison with theoretical
buckling loads for a perfect plate, closely agreeing
with previous theoretical work.
Experimental results in compression, both with
and without an artificially introduced imperfection, are
used to demonstrate real plate behaviour, and they enable
a comparison to be made with computed results. Measure-
ments of deflection are made by the Moire fringe tech-
nique, as well as by dial gauges.
The program is used to investigate the effect of
buckling on the compressive and shear stiffness of plates
with various degrees of imperfection, including the
compressive stiffness of a square plate after buckling
in shear.
