A procedure to select time-histories for shaking table tests on nonstructural components

Abstract

In the last years, the scientific community research effort is moving towards the investigation of the seismic behaviour of nonstructural components. In this paper, a procedure to select time histories to perform full-scale shaking table tests on nonstructural components is proposed. In particular, the experimental tests are designed and implemented to investigate the seismic behaviour of a typology of nonstructural components: the plasterboard continuous suspended ceilings. A set of five accelerograms, used as input for the shakings, are opportunely selected matching a target response spectrum or required response spectrum (RRS), provided by the USA code ICBO-AC156 "Acceptance criteria for seismic qualification testing of nonstructural components". The RRS is obtained as a function of the design spectral response acceleration at short periods, SDS, depending on the site soil condition and the mapped maximum earthquake spectral acceleration at short periods. The selection procedure is performed, for a RRS corresponding to SDS=1.50g; the so obtained record is then scaled to match other four levels of the target spectrum (corresponding to SDS 0.30g, 0.60g, 0.90g and 1.20g). These accelerograms, representative of different intensity levels, are then applied to a test setup opportunely designed and realized to perform the shaking table tests. Two typologies of continuous plasterboard ceilings are tested and three limit states (occupancy, damage and life safety limit state) are considered in this study to characterize the seismic response. The ceilings tested shows no damage at all intensity level (the acceleration on the ceiling ranges from 0.40g to 2.36g), resulting in a low fragility.