A STUDY ON THE STABILITY OF CIRCULAR SECTION STEEL STUB-COLUMNS IN THE PLASTIC-FLOW REGION

—Discrepancy between theory and experimental result for elephant-foot buckling—

Abstract

Maximum stress obtained by compression test of circular steel stub-columns were compared with deformation theory and incremental stress-strain theory. Each buckling analysis has a term of tangent modulus E_t in its solution. Therefore these solutions are commonly considered that all specimens lose stability in the plastic-flow region. This paper shows that specimens with small diameter-to-thickness ratio can be compressed beyond plastic flow region by reconsidering past plastic theories.