DYNAMIC SEISMIC TESTING OF LARGE SIZE STEEL DECK DIAPHRAGM FOR LOW-RISE BUILDING APPLICATIONS

摘要

A test program was carried out on 21.02 m x 7.31 m metal roof deck diaphragm specimens subjected to dynamically applied in-plane loading. The tests were conducted at different amplitudes of loading: low amplitude vibrations to characterize the dynamic properties of the specimens, variable amplitude excitations to evaluate the change in dynamic properties from elastic response up to yielding, and extreme seismic loading to examine the inelastic cyclic response. Three series of tests were performed: two on new steel roof deck assemblies and one on the first specimen that was repaired after being subjected to the extreme seismic loading condition. The diaphragm stiffness and fundamental period were found to vary significantly with the amplitude of the applied motion. Damage under the extreme loading condition concentrated at the fastener locations, which resulted in pinched hysteretic response and strength degradation. The tests showed that the original in-plane strength and stiffness of metal deck diaphragms could be restored if properly repaired, even after having sustained significant inelastic demand as was applied in the tests.