Design of flexibility-connected unbraced steel building frames

Abstract This paper summarizes an analytical study of framing systems for buildings with the purpose of thoroughly evaluating the Type 2 Design Procedure, as practised. The paper draws conclusions on the limits of applicability of Type 2 design, makes observations on some lacks in economy/safety of Type 2 frames, and proposes a simple, rational Modified Type 2 Design Procedure which enables designers to take advantage of connection stiffness in reducing girder sizes at the expense of increasing column sizes, but without requiring computer resources.