ASPECTS OF THE GLOBAL INELASTIC STABILITY OF FRAMES.

The paper first briefly outlines a method of analysis suitable for treating inelastic instability problems and then applies the method to study the limit behavior of two different structural systems. The nine structures examined are five-story, single bay structures subjected to proportional lateral and vertical loads in various combinations. The first three structures are moment resisting frames while the remaining six are eccentrically braced frames. The differences among the nine frames occur only in the cross sectional dimensions of the column members and the ratio of lateral load to vertical load. Emphasis is placed on determining the force deformation characteristics of the systems and evaluating the impact of column strength on the different buckling modes, and the rate of loss of carrying capacity in the post-limit regime.