What Is Braced Frame Structures?
What Is Braced Frame Structures?
A braced frame is a popular structural system utilized in buildings and structures that are exposed to lateral forces such as wind and seismic pressure. This type of system is commonly constructed with structural steel, known for its ability to withstand both tension and compression.
The beams and columns of a braced frame are designed to carry vertical loads, while the bracing system is responsible for transferring lateral loads.
One potential challenge with braced frames is that the positioning of the braces may impact the design of the building’s exterior, including the placement of openings.
Some architects have addressed this issue by incorporating the bracing into the building’s design as an aesthetic feature.
Types Of Braced Frame
Braced frames come in different types, with the most common being concentric braced frames. This type of bracing is characterized by the fact that the centroid of each member passes through the same point where the members intersect at a node.
Concentrically braced frames can be further divided into two categories: ordinary and special. Ordinary concentric braced frames (OCBFs) are typically used in areas with low seismic activity and do not have strict requirements for members or connections.
These types of steel frame buildings were first developed in Chicago, and reinforced concrete frames in Germany and France, where earthquakes were not a major concern.
Special concentrically or eccentrically braced frames, on the other hand, are used in areas with high seismic risk and have more demanding design requirements.
These designs are intended to ensure adequate ductility, meaning the ability to stretch without breaking suddenly.
Moment Frame Vs Braced Frame
A braced frame is a type of structural system in which pin connections are used to form the beam-column joints, and the bracing system is used to transfer lateral loads to the foundation. The analysis of a braced frame structure is easy and simple, and it is not labor intensive.
Braced frames are cost-effective and provide good stabilization to the structure, but they are mostly used in the construction of steel and timber structures.
A moment resisting frame is a type of structural system in which a rigid connection is used between beams and columns, and moments are transferred through the connection. The analysis of a moment resisting frame connection is fairly complex, and it is substantially labor intensive.
Moment resisting frames are expensive to construct and have less stability compared to braced frames but reinforced concrete structures inherently employ moment resisting frame. Beams and columns in a moment resisting frame are analyzed under axial loads and moments.
What Are Braced Frames Made Of?
Braced frames are a type of strong structural system that is mainly used in buildings and structures which are subject to lateral loads such as those due to wind or seismic pressure.
The members of a braced frame, which provide support against the forces exerted on them, are typically made up of structural steel; a material that helps resist both tension and compression forces.
Additionally, the bracing elements have been designed to work in conjunction with one another, making them an ideal choice for many structural applications when it comes to resisting lateral loads.