This thesis presents a number of studies on dynamic buckling of structural
elements under high velocity. The subject is studied here at great length with an
emphasis on identifying the important parameters that affect dynamic buckling and
how these parameters affect the stress, overall strain, and lateral deflection growth.
From an analysis of an ideally straight semi-infmite bar to one of a slanted
columnar member of a truss core, the dynamic effects on structural elements
reported here are recurring themes in all chapters, regardless of the boundary
conditions. The most notable cause of these effects is that of the coupling of the
plastic wave propagation and lateral column buckling. When the loading rate is
extremely high, these two phenomena are necessarily coupled. In this regard this
work is set apart from much of the earlier work on dynamic loading of columns
where the loading rates are an order of magnitude lower and it is assumed that the
axial stress state is established before buckling ensues.
When columns are loaded dynamically to high velocities, the momentum
imparted at one end causes stress and strain localization and a rise in the stress as
high as three times the quasi-static yield value. In addition, inertia serves to delay
buckling to varying degrees, dependent on the column's slenderness ratio and
boundary conditions. This buckling retardation results in an increase in the energy
absorption capability of columns and truss cores with columnar members.