What is a Moment Frame?
A moment frame is a box-shaped frame with special moment connections or joints that help in the resistance of wind and earthquake damage. The frame helps a building to flex as necessary to remain the building’s integrity. There are three types of moment frames: ordinary moment frames (OMF), intermediate moment frames (IMF), and special moment frames (SMF). The word “moment” in the term moment frame, or joint, refers to the moment of inertia placed on a building when in wind or earthquake conditions. A building faces two primary types of inertia. One is outer inertia caused by wind pressure. This is the same pressure applied to a person if they are standing in a strong wind. Inner inertia, like that from an earthquake, comes from the ground up. A person feels similar inertia when standing on a train that takes off quickly and they are shaken from the feet up. Buildings are intended to bend with moderate inertia and return to their former state. This is called elasticity. Just like a rub
