PSI - Issue 44

ScienceDirect Structural Integrity Procedia 00 (2022) 000–000 Structural Integrity Procedia 00 (2022) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceD rect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 44 (2023) 1474–1481

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy. Abstract During high magnitude ground motions, the internal lateral impact between inner sliders of frictional isolators and restraining rims of sliding surfaces may occur, jeopardizing the benefits of seismic isolation. In this study, a variable curvature friction isolator that exhibits a smooth-hardening behavior at large lateral displacements is evaluated as an alternative to mitigate the adverse effects of internal impacts. The geometry of the sliding surface is obtained by revolving a plane ellipse around a vertical axis. The pendular force transmitted by the isolator increases in stiffness as the device is laterally deformed. This research presents a physical model of variable curvature frictional isolators valuable for analyzing the three-dimensional dynamic response of structures equipped with variable curvature devices. The suggested physical model is capable of accounting for essential modeling features such as large deformations, P-∆ effects, sticking and sliding phases, uplift, kinematics constraints, and the lateral impact behavior. The presented force-displacement relationship of the frictional bearing with smooth-hardening behavior was validated using a Finite Element Model (FEM) under static and dynamic loads. An accurate representation of the coupling between the horizontal components of the pendular and frictional forces transmitted by the isolator is achieved by employing the physical model. The impact parameters of the physical model were calibrated to match the dynamics response of the FEM subjected to unidirectional and bidirectional ground motion inputs. Finally, a comparative example of a base-isolated three-dimensional structure is presented to show how the dynamic response is affected when variable curvature bearings form the isolation system. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy Keywords: V ariable curvature frictional isolator; physical model; internal impact; seismic isolation XIX ANIDIS Conference, Seismic Engineering in Italy A physical model for dynamic analysis of structures equipped with variable curvature frictional isolators Gaspar Auad a,b, *, José Luis Almazán b a Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin (10129), Italy b Pontificia Universi ad Católica de Chile, Vicuña Mackenna 4860, Santiago (8970117) Abstract During high magnitude ground motions, the internal lateral impact between inner sliders of frictional isolators and restraining rims of sliding surfaces may occ r, jeopardizing the be efits of seismi isolatio . I thi study, a variable curv u e friction isolator that exhibits a mooth-hardening behavior at large lat ral displace ents is evaluated a an alternative to mitigate the adverse effects of internal impacts. T e g ometry of the slidin surface is obtained by revolving a plane ellipse around a ver ical axis. Th pendular force transmitted by th isolator incr a es i stiffness as the d vice is laterally deform d. This esearch p esents a physical model of variable curvature fricti n l isolators valuable or an lyzing the three-dimensional dynamic response of struc ures equ pped with vari ble curvature dev es. The sugge ted physical model is capabl of accounti g for essential modeling features s ch as large deformations, P-∆ effects, sticking and sli ing phases, uplift, kinematics constraints, and the la eral impact beh vior. The pre ented force-displacement rela ionship of the frictional b aring with s ooth-hardening behavior was validated using a Finite Element Model (FEM) unde st c and dynamic loads. An accurate represen ation of the coupling between the horizont l components of the p ndular and frictional forces tr nsmitte by the isolator is achieved by employing the physical model. The impact arameters of th physic l model were calibrated to match dyn mic response of the FEM subjected to unidir ctional and bidi ectional ground mot on inputs. Finally, a comparative example of a ba e-i olated three-dimen ional structure s prese ted to show how the dynamic response is affected when variable curvatur bearing form the isolation system. © 2022 The Author . Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review u der re ponsibility of scientific committe of the XIX ANIDIS C nfere ce, Seismic Engineering in Italy K ywords: V ariabl curvature frictional isolator; physical odel; internal impact; seismic isolation XIX ANIDIS Conference, Seismic Engineering in Italy A physical model for dynamic analysis of structures equipped with variable curvature frictional isolators Gaspar Auad a,b, *, José Luis Almazán b a Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin (10129), Italy b Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago (8970117)

* Corresponding author. Tel.: +56 9 30831472 E-mail address: gaspar.auadalvarez@polito.it / gaauad@uc.cl * Corresponding author. Tel.: +56 9 30831472 E-mail address: gaspar.auadalvarez@polito.it / gaauad@uc.cl

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy. 10.1016/j.prostr.2023.01.189