01080500

Monograph

http://onlinepubs.trb.org.../NCHRP065_Final_Report.pdf

This Innovations Deserving Exploratory Analysis (IDEA) project developed seismic damping devices made of shape memory alloys (SMA) that can be applied to the retrofit of bridges. By concentrating energy dissipation in controlled locations, these devices can be used to reduce the demand on individual frames in a multiple-frame bridge, thereby enhancing the performance of these structures. This paper presents the results of an evaluation of the efficacy of using SMA restrainers to reduce the response of decks in a multi-span simply supported bridge. The results show that the SMA restrainers reduce relative hinge displacements at the abutment much more effectively than conventional steel cable restrainers. The large elastic strain range of the SMA restrainers allows them to undergo large deformations while remaining elastic. In addition, the superelastic properties of the SMA restrainers result in energy dissipation at the hinges. Finally, the results show that the SMA restrainer bars are extremely effective for limiting the response of bridge decks to near field ground motion. The increased stiffness of the SMA restrainers at large strains provides additional restraint to limit the relative openings in a bridge.

This NCHRP-IDEA investigation was conducted by the Georgia Institute of Technology, Atlanta. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

NCHRP-IDEA Project 65

English

45p

2002-2

NCHRP-IDEA Program Project Final Report

Final Report

Print

Figures; Photos; Tables (5)

Dissipation; Earthquake resistant design; Elasticity (Mechanics); Highway bridges; Rehabilitation; Retrofitting; Stiffness; Technological innovations

Innovations Deserving Exploratory Analysis (IDEA) (Program)

Restrainers (Bridges); Shape memory alloys; Superelasticity

Bridges and other structures; Design; Energy; Geotechnology; Highways; Materials; I24: Design of Bridges and Retaining Walls; I34: Steels and Metals

TRIS, TRB

Oct 30 2007 3:03PM