The webinar will begin with a general introduction on the topic of hazard-consistent assessment of steel frames and timber rocking structures.
Presentation 1: Hazard-consistent performance assessment of Steel Moment Frames (Faridah Zahra)
Steel Moment Resisting Frames (MRFs) are ductile structures characterised by their large lateral deformation capacity. Although much research has been done to date on the prediction of peak and residual deformations in MRFs, all modelling efforts have remained oblivious to the central issue of hazard consistency. Hence, missing the causal connection between the seismic hazard level and the ground-motion suite used and potentially compromising the meaningfulness of their results.
This presentation will call attention to the massive misrepresentations of peak and residual drifts observed when a proper consideration of hazard-consistent assumptions is not adopted. Finally, comparisons between the seismic performance of MRFs designed with the current and new Eurocode 8 as well as the American seismic code, the ASCE 7-16, are presented within a hazard-consistent point of view and conclusions are drawn on the efficiency of the proposed designs.
Presentation 2: Modelling structures with clutched inerter devices (Yixuan Zhang)
Inerters (ID) and Clutched Inerter Devices (CID) are an innovative technology with proven potential for seismic control. Nonetheless, the intrinsic non-linearity and discontinuity of the clutching mechanism in CIDs can create significant difficulties for their precise numerical modelling. Most currently available modelling methods either overly simplify the physics of dynamic contact or are highly sensitive to the step size, potentially leading instability or requiring considerable computational resources.
This presentation introduces an original formulation of the ID and CID element by means of a Mixed Lagrangian Formulation (MLF). The newly proposed MLF-CID element is then implemented into hazard-consistent estimations of MRF and self-centring rocking structures. The advantages of using the MLF are stressed, and the response of structures clutched inerters is discussed.
*Photo contributed by EERI members and California Earthquake Clearinghouse participants.
*Copyright Holder: Earthquake Engineering Research Institute (EERI)
