Slender concrete column analysis using direct methods

Current design formulas for slender concrete columns are inaccurate when failure is due to instability. Three direct methods, the energy method, collocation and finite differences, were applied to the problem in an attempt to obtain a design method suitable for code use. Of the three methods, the collocation method appeared to give the best results since the equations obtained from energy and finite differences were much too complex for the required degree of accuracy. The methods require the adoption of a suitable moment-curvature model, and it was found that a straight line and two parabola model could adequately represent the real moment-curvature relation.Applied Science, Faculty ofCivil Engineering, Department ofGraduat