Effect of nonstructural components on the dynamic characteristics of light-frame wood buildings

Abstract

This research deals with ambient vibration measurements (AVM) in 16 multi-storey light-frame wood buildings with wood-based shear walls as the main lateral load resisting system. Its primary objective is to evaluate the effect of nonstructural sheathing panels and the connectivity between firewall-separated buildings, on the modal properties of the tested buildings. Lower natural frequencies, corresponding mode shapes and equivalent structural damping were extracted from the AVM records. The study confirmed that the increase in stiffness of the finished buildings was dominant over their increase in mass when sway mode periods of finished buildings and bare structural frameworks are compared. The stiffening effect of gypsum wallboard was deemed significant and should be accounted for in seismic design. The study also indicates that even when the building section were only nominally connected to the firewall, composite action in the lateral response was taking place.