Abstract
In this research, dynamic buckling behavior of plate- and column- type long aluminum rods whose ends were tightly clamped and middle portions were free or supported was investigated experimentally in the transition velocity range : V = 0.001 to 1m/s, where the loading condition was changing from static to dynamic one. In the experiments, a hydraulic loading machine and a free fall drop-weight type impact testing machine were employed. Dynamic buckling loads at various velocities were measured by the load cell set on the push rod of the hydraulic loading machine or the load sensing block set just below the lower end of the specimen. On the other hand, displacements were measured by a high speed magnetic-resistance device. From experimental results, it was found that the dynamic- to static- buckling load ratio α were successfully described by a power low of slenderness ratio λ and the effective velocity Ve (=V- V0), where V0 is the lower critical or threshold velocity at which the effect of the axial and/or transverse inertia on the dynamic buckling load disappear and the dynamic buckling load becomes equal to the static buckling load. Furthermore, it was also shown that ζ, a ratio of the dynamic buckling load in the intermediately supported condition to the dynamic buckling load in the intermediately free condition, decreases from 4, that was the theoretical value of Euler's buckling equation, to 1 with the increasing slenderness ratio and effective velocity, and this ratio ζ was found to be well expressed by the exponential of slenderness ratio λ and the effective velocity Ve.
