Abstract
Nonlinear bending oscillation of RC column with softening of M-φ curve is dealt with in this paper. Simplified one mass system of column with weakly nonlinear M-φ relationship is modeled by Duffing equationand some typical behaviors of Duffing equation are shown in numerical results. And comparison of phase plane of horizontal displacement between actual results ofdynamic response of RC column and the results of Duffing equation has a good coincidence in the case of weakly nonlinear region of M-φ curve.
