Practical Second‐Order Inelastic Analysis of Semirigid Frames

Abstract

The stability behavior of rigid and semirigid frames bent in the weak axis is investigated using a hardening plastic hinge method. The stability limit load of frames is usually overpredicted by the simple plastic hinge analysis neglecting the effect of partial plastification. The plastic zone analysis can predict the limit load more accurately but a large number of elements must be used. Hence, it is costly and time‐consuming. An alternative method called the “hardening plastic hinge method” is developed here for practical use. In the proposed method, one element is used per beam‐column. The initial yield surface including residual stress is first determined from the normalized moment‐curvature‐thrust relationship of