Earthquake response modification of bridges using superelastic shape memory alloys
Bridges are susceptible to unseating of bridge decks and collapse under seismic loading.This problem can be remediated through retrofit,or rehabilitation,which alters the bridges response under earthquake loading.While a number of approaches for unseating prevention have been used in practice,limitations of traditional devices have been recognized.This paper presents an innovative retrofit approach for seismic response modification of bridges which exploits the unique characteristics of shape memory alloys(SMAs),namely the recentering ability of superelastic SMAs.Shape memory alloy restrainers capitalize on the superelastic nature of the material,among other potential advantageous qualities,in order to limit the deck displacements and relative hinge openings in bridge spans,and reduce the potential for collapse.Two phases of experimental testing are presented,which examine the viability of SMA restrainer cables.The first phase evaluates the impact of the devices in a representative in-span hinge of a multi-frame concrete bridge,and reveals the improved performance of the SMA cables relative to traditional steel restrainer cables.The experimental test data is compared to analytical studies,confirming the ability to model and capture the typical behavior of the SMAs.Finally,the response modification device is tested in a large-scale,four-span bridge.Preliminary results reveal the positive impact of using SMA restrainers and indicate the advantage of prestraining the cables.
bridge retrofit shape memory alloys response modification earthquakes
J.E. Padgett R. DesRoches
Georgia Institute of Technology,Atlanta,GA
国际会议
The World Forum on Smart Materials and Smart Structures Technology(SMSST07)(2007年世界智能材料与智能结构技术论坛)
重庆·南京
英文
2007-05-01（万方平台首次上网日期，不代表论文的发表时间）