Moment-resisting frame

Definition

A moment-resisting frame is a structural system designed to withstand lateral forces, such as those generated by earthquakes, by allowing the frame to bend and sway without collapsing. This system relies on rigid connections between beams and columns, enabling the frame to maintain its shape and resist deformation under load. Moment-resisting frames are integral in the design of buildings in seismic regions, ensuring structural integrity during dynamic loading events.

5 Must Know Facts For Your Next Test

1. Moment-resisting frames are designed to allow buildings to sway during an earthquake, helping to prevent structural failure and collapse.
2. The rigidity of the connections in a moment-resisting frame is crucial; they must be strong enough to transfer forces between beams and columns effectively.
3. These frames can be constructed from various materials, including steel and reinforced concrete, each offering different advantages in terms of strength and flexibility.
4. In regions with high seismic risk, moment-resisting frames are often combined with other lateral force-resisting systems, such as shear walls, to enhance overall stability.
5. The design philosophy behind moment-resisting frames emphasizes energy dissipation, allowing structures to absorb and dissipate energy from seismic forces rather than simply resisting them.

Review Questions

• How do moment-resisting frames function to provide stability during an earthquake?
  • Moment-resisting frames function by allowing the structure to flex and sway without collapsing when subjected to lateral forces from an earthquake. The rigid connections between beams and columns enable the frame to maintain its shape and resist significant deformation. This flexibility is crucial in absorbing energy generated by seismic activity, which helps prevent structural failure and ensures occupant safety.
• Discuss the importance of ductility in the design of moment-resisting frames and its impact on performance during seismic events.
  • Ductility is essential in the design of moment-resisting frames as it allows these structures to endure significant deformations without immediate failure. During seismic events, a ductile frame can absorb and dissipate energy effectively, providing time for occupants to evacuate safely. The ability to deform without breaking ensures that the building can withstand repeated stress during shaking, making ductility a key factor in enhancing the overall performance of moment-resisting frames.
• Evaluate the relationship between moment-resisting frames and other lateral force-resisting systems in achieving overall building safety during earthquakes.
  • The relationship between moment-resisting frames and other lateral force-resisting systems is critical for achieving comprehensive building safety during earthquakes. While moment-resisting frames offer flexibility and energy dissipation through their rigid connections, shear walls provide additional stiffness and strength against lateral forces. By integrating both systems into a building's design, engineers can create a robust framework that maximizes stability and minimizes the risk of collapse during seismic events. This combined approach reflects a deeper understanding of how various structural elements interact under dynamic loads.

Related terms

Shear wall: A vertical structural element that provides lateral support to a building by resisting shear forces, often used in conjunction with moment-resisting frames.

Ductility: The ability of a material or structure to undergo significant plastic deformation before failure, an essential characteristic for moment-resisting frames during seismic events.

Seismic design: The process of designing structures to withstand seismic forces, which includes considerations for the use of moment-resisting frames and other lateral force-resisting systems.