Effectiveness of Tuned Mass Dampers against Ground Motion Pulses

It is known that the effectiveness of tuned mass dampers (TMDs) decreases as the input duration shortens. As a result, their use is commonly discouraged against short-duration, pulse-like ground motions, such as those occurring in near-field (NF) zones in the presence of forward directivity or fling-step effects. Yet a systematic assessment of such control impairment is still missing. In this paper, a recent analytical model of ground motion pulses is applied to the design and evaluation of TMDs against impulsive earthquakes. Based on this model, first, a new optimization method is introduced as an alternative to the classical H-infinity approach. Then, the two strategies are tested on single- and multi-degrees-of-freedom linear structures subject both to analytical pulses and to a large set of NF records possessing pulse-like features. The resulting statistical evaluation, expressed by percentile response spectra, shows the pros and cons of a pulse-oriented TMD design and improves the general understanding of TMD performance under impulsive ground motions. DOI: 10.1061/(ASCE)ST.1943-541X.0000629. (C) 2013 American Society of Civil Engineers.