Stability of Sway-Inhibited Prismatic Columns Subjected to Internal Axial Loads

AbstractPrismatic members subjected to internal axial loads exist widely in engineering applications. Because the effects of internal loads and end loads on stability are quite different, the traditional effective length method is not applicable. Engineers require an efficient and convenient method for solving the stability problem of such members. A two-bar model is proposed to illustrate the concept that the effect of compressive axial loads on the stability of sway-inhibited columns can be understood as a negative lateral stiffness. After obtaining the expression of negative lateral stiffness, a relationship between end loads and internal loads can be established so that the internal loads can be considered equivalent to end loads. Then, the column subjected to internal loads can be analyzed as a normal column (without internal axial loads), and the critical buckling load can be obtained easily with the Euler formula. Eigenvalue buckling analyses were performed to examine the proposed method, and the c...