Structural Analysis and Design

The design of a frame and its components is a two‐step procedure involving a global frame analysis followed by individual cross section and member design checks. Traditionally, frame analysis is performed by assuming joints as perfectly pinned or perfectly rigid. It is important that the joints are subsequently designed and detailed to behave in a way that corresponds to the analysis assumptions. This chapter focuses on joint modeling, joint classification, joint idealization and ductility classes. Joint behaviour affects the structural frame response and, therefore, has to be modelled, just like beams and columns are modelled for frame analysis and design. The chapter introduces three different types of joint modelling: simple, semi‐continuous and continuous. One of the most simple idealisations possible is the elastic‐perfectly‐plastic one. For beam and column sections, deemed‐to‐satisfy criteria allow the designer to determine the class of the sections and therefore the type of global frame analysis which can be considered.