A formulation of the stability problem for tall unbraced frames, deformed b
eyond their elastic limit, has been developed using transfer matrices. A li
near incremental solution procedure allows the monitoring of plastic hinge
formation and the resulting reduction of the member stiffness until the cri
tical load is located. The most important second order effects arising from
large deformation have been accounted for. Simple modeling of inelastic be
haviour has been adopted although further refinement of the formulation at
no significant computational cost is indicated. Extensive application of th
e developed computer algorithm and comparison of its predictions with other
analytical results confirms the validity of the proposed method of solutio
n. (C) 1999 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved.