Structural Design Using Catalog Components

This chapter first describes how logically connected structural steelwork may be built up in Modelby choosing Components from the Catalog. Such structures will normally exist in the Modelhierarchy at Framework (FRMW) or Subframework (SBFR) level. The concepts are then extended for use in building designs, using other materials such as concrete.

The principal types of element involved in steelwork design are:

Nodes

These define the points within the 3D design model between which steel construction members are to run. Primary Nodes have their position defined in free space, whereas Secondary Nodes have their position defined relative to an owning steel Section. Nodal data, including the attributes of member elements of Nodes, is particularly relevant for stress analysis of the steelwork structure.

Sections

Sections represent the physical steel members (columns, beams, bracing struts) which make up the interconnected structure. Their cross-sections are defined by reference to Catalog 2D Profile elements, while their lengths are derived from the positions of the Nodes between which the Sections run.

Joints

These are Catalog items which represent the physical connections between structural members. Primary Joints are owned by Primary Nodes; Secondary Joints are owned by Secondary Nodes. Multiple connections are represented by Primary or Secondary Compound Joints, which own a SubJoint for each connection point. Linear Joints are used to connect the edges of panels to structural sections or to other panels.

Panels

Panels represent any sheet materials used to clad a structural model. Their shape is determined by linking together a set of Panel Vertex elements to form a 2D Panel Loop, which is then extruded in the third dimension to give the required panel thickness.

Fittings

Steelwork Fittings and Panel Fittings are Catalog items which can represent any ancillary item related to, but not an inherent part of, the structure, such as web stiffeners, lifting lugs, access ports, and so on. They are owned by Sections and Panels, respectively. Compound Fittings and Compound Panel Fittings, each of which owns Sub-fittings, are used to represent more complex geometry (such as penetrations, where one or more elements pass through another element).

Generic Sections (GENSECs)

GENSECs can be used to represent any structural item whose geometry can be generated by sweeping a 2D profile along a linear or curved path. The path, defined by a Spine element, is determined by a sequence of Spine Points and Curves. In their simplest linear format, GENSECs may be used instead of Sections and Panels; in more complex formats they can represent curved beams, curved walls.

Fixings

Generic fixings can represent any joint or fitting owned (indirectly) by a GENSEC.