Features
A classic single-bay frame structure consists of two columns and a beam, which connects both columns. For stiffening, such a frame requires at least one rigid connection, whereby one or both frame joints are selected as usual.
Rigid frame joints ensure the stability in the sense of impossibility to displace the frame structure, so that bracing due to tie rods are usually omitted.
Furthermore, the rigid frame joints can absorb bending moments, whereby the moment in the beam span is minimized and a higher span can be achieved here.
Application
Frame structures can also have two or more aisles, that is, be built in length or width, as well as arranged on top of each other.
Examples:
- Multi-aisle: Logistics halls
- On top of each other: Multi-story buildings, parking garages
Since the frame structures are mainly subjected to bending, there are usually specific cross-section reinforcements (tapers) in the area of the frame joint. Due to the higher stiffness, the moments are "tightened" at this location and reduced at the other locations, such as in the middle of the span, see Image 01.
A rigid frame joint is either welded or bolted. Furthermore, it is conventional to arrange web ribs, if necessary, so that the compressive forces resulting from bending moments are more favorably directed from the beam into the column without too large bending of the column flange, see Image 02.
Frame Structures / Frame Joints in RFEM and RSTAB
Dlubal Software provides RFEM and RSTAB as main programs that allows you to intuitively model all different member structures and to calculate internal forces, deformations, and support forces. The add-on modules RF-/JOINTS Steel – Rigid and RF-/FRAME JOINT Pro are suitable for design of frame joints.
See Also
- Beam Structure
- Truss
- Arched Structure