Seismic analysis of steel frame wood panel shear walls

The use of steel frame/wood panel shear walls as a seismic force resisting system (SFRS) in residential and/or commercial buildings is expected to increase in the future. At the moment, in Canada, however, no specific guidelines in line with the seismic provisions of the National Building Code of Canada (NBCC) exist with which the engineer can design a building consisting of these shear walls. An extensive research program has therefore been undertaken at McGill University to develop a design method through the testing of different configurations of steel frame/wood panel shear walls loaded with monotonic and reversed cyclic protocols. A total of 16 wall configurations (109 walls) were tested over the course of the study. The CUREE Ordinary Ground Motions loading protocol was selected to represent the reversed cyclic regime because it was found to best correspond to the demand that would be imposed on a steel frame I wood panel shear wall during a typical seismic event.The analysis of test results in order to extract the principal design information was carried out using an Equivalent Energy Elastic-Plastic (EEEP) model. A ductility related (Rd) and an overstrength related (Ro) force modification factor are required for the calculation of equivalent static seismic loads following the 2005 NBCC design provisions. Values of Ro = 1.8 and Rd = 2.5 have been determined and are recommended on a preliminary basis.The Stewart hysteretic model was found to best represent the strength and stiffness characteristics of a steel frame/wood panel shear wall component. The subsequent evaluation of building models that incorporate the Stewart model using non-linear time history dynamic analyses could then be carried out to validate the assumptions made by the EEEP method on the system ductility and the corresponding force modification factors