City Research Online

Abstract

The design of seismic protective devices (SPDs), such as fluid viscous dampers (VDs), and inertial vibration absorbers (IVAs), requires the adoption of appropriate models for: (i) the earthquake excitation description (e.g. stochastic stationary/non-stationary versus recorded ground motions); (ii) the seismic structural response estimation (e.g. linear versus nonlinear/hysteretic); and (iii) the seismic performance quantification (e.g. average response versus risk-based performance description). This paper pursues a novel detailed investigation of the impact of modeling fidelity in the design of SPDs, by examining different combinations of models with different levels of sophistication for each of the aforementioned aspects. In this manner, a large model hierarchy is established, resulting in multiple SPD design variants. A bi-objective optimal design formulation is adopted, considering the competing structural vibration suppression (building performance) and device control forces as distinct performance objectives (POs). Comprehensive comparisons are reported for a 3-storey and a 9-storey steel benchmark building, equipped with distributed VDs in all floors and with different types of single-device IVAs including the tunedinerter-damper (TID), the tuned-mass-damper-inerter (TMDIs) and the tuned-mass-damper (TMD). An innovative methodological approach is established to gauge the impact of the model fidelity by examining the deviation of POs achieved by lower fidelity SPD designs versus the Pareto-optimal fronts corresponding to POs consistent with the higher fidelity assumptions. It is found that the TID is more robust than the TMDI to design modelling assumptions, suggesting that more lightweight IVAs (where majority of secondary mass is replaced by inertance property) relax requirements for high-fidelity models in device tuning. It is further found that large force VDs installed in each building floor are significantly more robust to the design fidelity modelling than single IVA implementations at the expense of increased costs to accommodate the larger number of devices. Consideration of structural nonlinear response becomes important in the SPD design when combined with risk-based performance quantification as opposed to average performance (i.e. the popular H2 design). Moreover, the risk-based performance of nonlinear structures becomes sensitive to the use of recorded ground motions (GMs) as opposed to artificial GMs with only time-domain non-stationarity, as well as to the number of recorded GMs used. The study overall stresses that that the use of lower fidelity models may provide sub-optimal performance in certain settings, and that comparison across the model hierarchy can be leveraged to obtain key insights of the SPD behavior. Additional key findings pertain to the robustness characteristics of the different type of SPDs to the modeling assumptions utilized for the device design.

Publication Type:	Article
Additional Information:	© 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
Publisher Keywords:	seismic protective device design; model fidelity; risk-based design; non-stationary performance; reduced order modeling
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TH Building construction
Departments:	School of Science & Technology > Engineering
SWORD Depositor:	Symplectic Administrator

Export

Downloads