Shake table testing of braced and Friction-Added suspended ceilings and associated numerical study

•Shake table tests were conducted for unbraced and braced ceiling specimens.•Limitations and side effects resulting from ceiling braces were discussed.•A novel ceiling friction damper was developed, and its performance was evaluted.•The proposed friction damper showed a highly enhanced seismic performance.•A numerical study was conducted using a simplified friction ceiling model. Suspended ceilings have long been shown as one of the most fragile non-structural components during past earthquakes. Under high seismic application, suspended ceilings are often required to be restrained using ceiling braces. However, because of the complicated behavior of suspended ceilings under seismic loading, the efficiency of braced ceiling systems is still unclear, and effective performance-enhancing methods for suspended ceiling systems have not yet been established. In this study, shake table tests were first conducted for unbraced (or non-seismic) and braced suspended ceiling specimens. Despite the seismic bracing according to ASTM E580, substantial damage, comparable to the non-seismic ceiling specimen, was observed in the braced ceiling specimen because of the lack of rigid diaphragm action of the tested ceiling grid. In order to enhance the seismic performance of a non-seismic suspended ceilings cost-effectively, a novel rotational friction mechanism was added, and its effectiveness was experimentally evaluated. The proposed friction damper exhibited a stable hysteretic behavior under various input motions and effectively improved the seismic performance; only minor damage was observed at the ceiling perimeters. The friction damping parameters, such as the maximum static friction force, were experimentally calibrated, and an analytical model of the friction-added ceiling system was developed. A numerical case study was conducted to evaluate the applicability of the proposed friction-added ceiling system based on an extensive time history analysis of steel moment-frame buildings.