Equivalent Number of Loading Cycles for the Seismic Testing of Passive Energy Dissipation Devices
Fahim Sadek, Michael A. Riley
Prototype testing of passive energy dissipation devices is required to verify their response characteristics and demonstrate their capacity to withstand the design loads. These tests usually consist of loading the devices with a defined number of cyclic loads, with frequency and amplitude based on the design properties. The objective of this research was to develop recommendations for the required number of sine-wave-equivalent loading cycles that a device will be subjected to during the design earthquake. For this purpose, several linear and nonlinear single-degree-of-freedom (SDOF) structures were analyzed with a large number of earthquake records and the required number of cycles was computed based on two criteria. The first criterion is the equivalent total energy, where the energy dissipated by the passive energy dissipation device during seismic excitation is equal to that absorbed by the device during cyclic testing. The second criterion is the equivalent cumulative displacement, where the cumulative displacement experienced by the device during seismic excitation is equal to that experienced by the device during cyclic testing. Two sets of earthquake records were included in this study: a general set and a near-source set. The results of the various analyses indicated that the number of loading cycles computed using the displacement criterion is significantly larger than that based on the energy criterion. Comparing the number of cycles computed for linear and nonlinear structures, it is found that increased nonlinearity results in a smaller number of cycles using both criteria, due to the energy dissipated through inelastic action. The results also indicate that similar numbers of cycles are required for near-source and far-field ground motions in the short-period range, while for longer periods (T > 1 s), near-source excitations require fewer cycles.
Proceedings of 7th U.S. National Conference on Earthquake Engineering
July 21-25, 2002
Proceedings of the 7th U.S. National Conference on Earthquake Engineering
and Riley, M.
Equivalent Number of Loading Cycles for the Seismic Testing of Passive Energy Dissipation Devices, Proceedings of 7th U.S. National Conference on Earthquake Engineering, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860447
(Accessed December 10, 2023)