Bracing requirements of inelastic columns

Various types of braces are used to prevent buckling of structures and incr ease buckling strength. While bracing requirements of elastic structures ar e well explained, those of inelastic structures are not fully developed. Ex perimental and analytical studies were conducted to determine bracing requi rements of inelastic columns. In the experimental study, columns with a bra ce at mid height were loaded to their maximum limit with the brace stiffnes s at the mid height as the main variable. The tangent modulus of the column s which governs the inelastic buckling loads was kept constant. An analytic al study was also performed to compare with the experimental results. The c olumns were modeled and analyzed by the finite element program, ABAQUS. It was found through the experimental and analytical studies that the bracing requirements for inelastic columns depend on the number of braces, the buck ling load, and the length of a column but not on the material state. The re sults show that Winter's simplified method to determine full brace requirem ents can be applied to inelastic members as well as elastic members. (C) 19 99 Published by Elsevier Science Ltd. All rights reserved.