Abstract
This paper presents a dynamic experimental approach for the reappearance of bulge local buckling phenomenon of steel tubular stub column with nonuniform thickness around the thickness transition section. First, steel tubular stub columns are manufactured following the occurrence condition of bulge local buckling phenomenon which was previously investigated by the authors for geometric parameter (diameter to thickness ratio, thickness to thickness ratio, and length to diameter ratio). Then, the impulsive push-up test was performed for the specimens, and it is confirmed that the bulge local buckling occurrs around the section where thickness of the specimen changes, and external force conditions such as push-up veleocity and push-up forced displacement are investigated. Finally, a dynamic plastic local buckling stress formula is proposed based on the plastic local buckling load obtained from the impulsive push-up test by introducing strain rate effects into static formula, and the validity of the proposed formula is verified through the comparison with the test results.
