ABSTRACT
When a tubular cantilever beam is loaded by a dynamic force applied transversely at its tip, the strain hardening of the material tends to increase the load carrying capacity and local buckling and crosssectional overlization occurring in the tube section tends to reduce the moment carrying capacity and results in structural softening. A theoretical model is presented in this paper to analyze the deformation of a tubular beam under a dynamic response mode. Based on small deflection analysis, the hardening/softening M-K relationship is introduced under the assumption that the plastic energy dissipated at a plastic hinge in a rigid-perfectly plastic model equals that dissipated in a plastic zone in a hardening/softening model. The main interest is on the curvature development along the beam.
