NOTIONAL-LOAD PLASTIC-HINGE METHOD FOR FRAME DESIGN

The present paper discusses the use of second-order inelastic analysis for designing steel-frame structures. In particular, the elastic-plas tic hinge method is discussed and its accuracy is examined. The elasti c plastic-hinge analysis does not always represent accurately the inel astic behavior of a member, since it does not account for distributed plasticity and initial residual-stress effects. One way to account for these effects in the analysis is to apply a set of notional lateral l oads that are computed based on the gravity loads acting on the storie s of the frame. The performance of this analysis approach is compared with the results from conventional elastic plastic-hinge and refined p lastic-zone solutions. The goal is to illustrate the acceptability of the notional-load plastic-hinge method for use in predicting the maxim um strengths of steel frames and their members. Finally, the design im plication of this approach is explained, and its extension for the ana lysis and design of multistory and multibay frames is discussed.