For years steel moment frames have been a common method of providing high lateral-force resistance when limited wall space and large openings control the structural design. Ordinary moment frames consist of beams and columns, typically connected by a combination of bolts and welds to form rigid joints. The frames resist lateral loads primarily through bending in the beams and columns.
Stronger than site-built or factory-built shearwalls, moment frames allow larger openings and smaller wall sections while still providing the loads structural designers need. Moment frames are commonly used in applications such as garage fronts, large entry ways, walls with large, numerous windows, tuck-under parking and great-rooms.
Traditionally, moment frames have been time-intensive to design and labor-intensive to install. Simpson Strong-Tie has taken these factors into consideration and has created a cost-effective alternative to traditional frames — the Strong Frame® ordinary moment frame.
Use of ordinary moment frames is permitted in Seismic Design Categories A, B and C without limitations and Seismic Design Categories D, E and F, subject to the limitations set forth in ASCE 7-05 Sections 188.8.131.52, 184.108.40.206 and 220.127.116.11. Ordinary moment frames may also be combined with other lateralforce resisting systems in accordance with ASCE 7-05 Section 12.2.2 and 12.2.3.