162,273 research outputs found
Modeling the Seismic Protection of the Updated Cable-Stayed Bridge Benchmark with Roll-N-Cage Devices
No full textThis work presents and assesses a reduced model of a recently proposed seismic isolation system, namely the Roll-N-Cage one. This system incorporates several interesting features and mechanisms in a single unit; among the others: isolation, energy dissipation, buffering, high vertical stiffness and strength for supporting heavy loads. Departing from previous studies, which were based on the simulation of the Roll-N-Cage device by uncoupled orthogonal unidirectional models, this work first introduces a reduced order coupled bidirectional numerical model of the device. Then the efficiency of such type of control devices, as simulated by the proposed approach, is evaluated for the seismic protection of a cable supported bridge. The bridge model is derived from the ASCE benchmark cable-stayed bridge by mean of an extended version
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Seismic protection of the ASCE updated cable-stayed bridge benchmark with RNC passive devices
No full textA new seismic isolation system, namely the roll-n-cage (RNC) isolator, has been recently introduced. A numerical and experimental campaign has been developed to study the mechanical behavior of a device prototype. The main goal of this work consists in evaluating the efficiency evaluation of such type of control devices for the seismic protection of cable supported bridges
Modelling the Axial Response of the Roll-N-Cage Device for Seismic Isolation
No full textThe present study focuses on the axial characterization of the Roll-N-Cage isolation device. The
procedure consists into two main steps: (i) laboratory investigations of a scaled prototype of the Roll-
N-Cage system for evaluating the mechanical cyclic response to axial compression and tension; (ii)
the development of a numerical model for investigating the reproduction of the strong unsymmetrical
axial response of the device. The proposed numerical model reposes on a modified form of the Wang
and Wen model by supplementing it with user identified scaling functions
Active and semi-active control of structures: a review of recent advances
No full textThe concepts of active and semi-active structural control in civil and infrastructure engineering date back 40
years. Periodically, state-of-the-art manuscripts have been published and technical books were also printed to testify the
maturation of the topic. This report only covers the last two years of theoretical, numerical and experimental studies, as well as
the use of control algorithms and devices in actual implementations. It is observed that there are still operational limitations to
prevent from the expected growth of the applications in standard design. Some innovative concepts help to foresee future
developments within special sectors of applications
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Characterization, modeling and assessment of Roll-N-Cage isolator using the cable-stayed bridge benchmark
No full textThis paper presents the results of an extensive series of simulation tests to identify the mechanical characteristics of an innovative isolation device known as the Roll-N-Cage (RNC) isolator. The seismic performance of an RNC passive control scheme is subsequently investigated on a model of the cable-stayed bridge benchmark. Starting from different configurations studied in the laboratory for a 1/10 reduced-scale prototype, the RNC isolator stiffness and damping properties are investigated in terms of cyclic tests with different parameters. Tests at the ultimate level state consisting of monotonic shear and axial loading have been also carried out as a part of the qualification process. The goal of this study is twofold: first, to examine the main integrated mechanisms of the RNC isolator through sophisticated 3D finite element simulation models using a multi-purpose finite element code. The main result of this step is to attempt modeling the force–displacement relationship using the standard Bouc–Wen model of smooth hysteresis. The second aim of this study is the numerical assessment of the device efficiency through its implementation into a bridge model considering several ground motions as external excitations. Based on these extensive studies, it was found that the RNC isolator is promising as a reliable isotropic horizontal isolation device for bridge structures.Peer ReviewedPostprint (published version
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