Comportamiento sísmico de las uniones metálicas en pórticos de nudos rígidos. El terremoto de Northridge

Seismic behavior in frame-moment connections Nortridge earthquake

Steel has many advantages comparing it with other structural materials. Steel behavior is very well known and it can assess a great quality because most of the components are made in the workshop. Steel seismic behavior is more predictable than other materials. Moreover, after an earthquake the damages in steel structures are easy repair. However, a structure made of steel is not a guarantee to behave well during an earthquake. We will get a good seismic response if the structural configuration is stable and if the elements and connections are able to dissipate the seismic energy. We have to guarantee a good energy dissipation through the structural design, trying to avoid the steel structure collapse. Rotational capacities in the beam to columns connections greatly affect the energy dissipation capacity of a moment-resisting frame. During Northridge earthquake, many brittle fractures appeared in the beam to column connections, and plastic hinge did not develop. The present paper examines changes in the professional practice after Northridge and some new procedures to guarantee the ductility in beam to column connections, in new frames and damaged frames.