Macro-Elements for Composite Beam-Column Connections

The behavior of macro-elements can be described by a set of orthogonal boundary states, each consisting of displacements and forces associated by a one-dimensional constitutive relationship. Combinations thereof are described by surface models in the force space with flow rules. Local models describing the mechanics inside the element are not restricted in detail and are needed only once to develop the constitutive relationships, surfaces models and flow rules: The problem is scaled in a mechanically consistent manner without loosing information or accuracy. A macro-element for a plane beam-column connection has five orthogonal states: Two bending, two normal and one shear state, if linear boundary displacements are assumed. These “beam-type” boundaries enable the connection to any beam element. Thus, it can be included in regular frame analysis greatly improving its accuracy. To demonstrate this powerful scaling technique, typical component models for beam-column connections are used to develop a “beam-type” macro element.