Elastic Buckling Loads of Fixed Frames By The Newmark Method

A numerical method for the solution of the elastic stability of fixed frames is presented. The Newmark iterative procedure to perform elastic buckling analyses for isolated columns is extended for use in computing buckling loads and buckling modes in frames with fixed columns. The method is illustrated in details by means of different cases of single-storey portal frames commonly used in commercial buildings. Compari-sons of obtained results with other well known methods show very good agreement.