A Nonlinear-Analysis-Based Procedure for Evaluating Load-Carrying Capacity of In-Plane Steel Frames

A simple method based on geometrically nonlinear analysis is proposed to evaluate the load-carrying capacity of a steel structure. The effects of material nonlinearity and residual stress are not included directly in the analysis, but are taken into account by introducing a fictitious initial crookedness on the structure. This crookedness, called the equivalent initial crookedness, is of crucial importance in the proposed method. The appropriate degree of crookedness is determined so as to give a satisfactory column strength. The applicability of the proposed method to practical design procedure is demonstrated by analyzing frame structures.