Seismic behaviour of a bracing system for LWS suspended ceilings: Preliminary experimental evaluation through cyclic tests

The results of a preliminary experimental study carried out to evaluate the seismic behaviour of a bracing system, designed to reduce the seismic vulnerabilities in lightweight steel (LWS) suspended ceilings, are presented in the current paper. The experimental investigation involved 12 cyclic tests on the bracing system carried out according to FEMA 461 loading protocol. A special test set-up for a universal testing machine was designed to test the system under two different directions of the horizontal seismic action, which could cause one or two braces of the bracing system to act as an element under tension. Test results were analysed in terms of strength, stiffness and damage phenomena. The study also demonstrates that a preliminary evaluation of the experimental cyclic response of a bracing system for LWS suspended ceilings under horizontal seismic actions can be performed by using a universal testing machine. Two case studies were developed in order to give preliminary information about the evaluation of the maximum ceiling area that a single bracing system can cover. The two case studies are residential reinforced concrete six-storey buildings located in two different geographical locations in Italy: Naples and L'Aquila, which are characterized by medium-high (0.17 g) and high (0.26 g) intensity of seismic loads, respectively. Based on the assumption of a weight for the ceilings in the range from 50 to 150 N/m2, a ceiling area ranging from 5.5 to 32 m2 was defined as the maximum area that a bracing system can cover.