Seismic vulnerability and loss assessment of an isolated simply-supported highway bridge retrofitted with optimized superelastic shape memory alloy cable restrainers

2020 ◽  
Vol 18 (7) ◽  
pp. 3285-3316 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jing-quan Wang ◽  
M. Shahria Alam
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Seismic Vulnerability ◽  
Highway Bridge ◽  
Loss Assessment ◽  
Simply Supported

Seismic Vulnerability Assessment of a Multi-Span Continuous Highway Bridge Fitted with Shape Memory Alloy Bars and Laminated Rubber Bearings

2012 ◽  
Vol 28 (4) ◽  
pp. 1379-1404 ◽  
Author(s):  
M. A. Rahman Bhuiyan ◽  
M. Shahria Alam
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Longitudinal Direction ◽  
Bridge Piers ◽  
Highway Bridge ◽  
Seismic Vulnerability Assessment ◽  
Rubber Bearings ◽  
Bridge System

This study performs seismic vulnerability assessment in the longitudinal direction of a three-span continuous highway bridge, restrained by shape memory alloy (SMA) bars and isolated with laminated rubber bearings. The analytical simulation method based on incremental dynamic analyses is used in evaluating the seismic fragility functions of the bridge components (pier and isolation bearing) and the system. A two-dimensional finite element model scheme with nonlinear force-displacement relationships is used for the bridge piers and bearings. This study shows that the bridge piers with SMA bars have led to relatively higher seismic vulnerability over the bridge piers without SMA bars, which is also reflected in the bridge system. The isolation bearings with SMA bars have revealed comparatively less seismic vulnerability than those without SMA bars. From the numerical results, it is recognized that the failure probability of the bridge system is dictated by the bridge pier over the isolation bearing.

Modeling of a Shape Memory Alloy Beam and its Stochastic Chaos

2013 ◽  
Vol 479-480 ◽  
pp. 215-219
Author(s):  
Gen Ge ◽  
Jia Xu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nonlinear Damping ◽  
Nonlinear Characteristic ◽  
Van Der Pol ◽  
Simply Supported ◽  
Stochastic Chaos ◽  
Strain Stress ◽  
Stress Relation ◽  
Hysteretic Cycle

The van-der-pol hysteretic cycle was applied to describe the hysteretic nonlinear characteristic of the strain-stress relation of a shape memory alloy (SMA). A new model with nonlinear damping of a simply supported SMA beam was proposed. The Criterions determining the stochastic chaos is obtained by the random Melnikov approach. The numerical results show the effectiveness of the theoretical analysis. Clear fractal boundaries of the system's safe basin is observed.

Seismic Fragility Assessment of Concrete Bridge Pier Reinforced with Superelastic Shape Memory Alloy

2015 ◽  
Vol 31 (3) ◽  
pp. 1515-1541 ◽  
Author(s):  
A. H. M. Muntasir Billah ◽  
M. Shahria Alam
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Plastic Hinge ◽  
Bridge Pier ◽  
Performance Criteria ◽  
Demand Model ◽  
Permanent Displacement ◽  
The Impact

In an attempt to reduce permanent displacement and damage, a hybrid reinforced concrete (RC) bridge pier configuration is considered in the present study. The plastic hinge region of the bridge pier is reinforced with superelastic shape memory alloy (SMA) and the remaining portion with regular steel. This paper focuses on fragility-based seismic vulnerability assessment for a SMA-RC bridge pier considering residual displacement, displacement ductility, and performance criteria as the demand parameters. Fragility curves are developed to assess the relative vulnerability of a SMA-RC bridge pier and a conventional steel-RC bridge pier using probabilistic seismic demand model (PSDM). The fragility curves are developed with a suite of 20 near-fault ground motions using incremental dynamic analysis. The fragility curves provide insight into the failure probability of the bridge piers and aid in expressing the impact of SMA on the bridge pier vulnerability.

Performance-based seismic loss assessment of isolated simply-supported highway bridges retrofitted with different shape memory alloy cable restrainers in a life-cycle context

2020 ◽  
Vol 31 (8) ◽  
pp. 1053-1075 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jingquan Wang ◽  
M Shahria Alam
Keyword(s):  
Life Cycle ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Highway Bridges ◽  
Niti Shape Memory Alloy ◽  
Widespread Application ◽  
Simply Supported ◽  
Seismic Loss ◽  
Structural Applications

Shape memory alloy cables have emerged as an alternative to conventional steel cable restrainers for preventing the bridge spans from unseating during an extreme earthquake. Feasibility of high-cost NiTi shape memory alloy restrainers in retrofitting the bridges has been numerically investigated, and promising results have been published; however, considering the economic impacts, the effect of different types of shape memory alloy such as Cu-based and Fe-based shape memory alloy restrainers has not been discussed yet. The objective of this study is to address this problem in detail in order to propose the most cost-effective shape memory alloy restrainer suitable for bridge engineering applications. Seismic fragility and life-cycle loss (both direct and indirect) assessments are analytically performed on an isolated simply-supported highway bridge retrofitted by four types of shape memory alloy restrainers (i.e. NiTi, FeNiCoAlTaB, CuAlMn, and FeMnAlNi). Results showed that for all retrofitted bridges performed in the range of design displacement, the effect of type of shape memory alloy is significant on the damage probability and long-term seismic loss of the bridges. All the bridges retrofitted with shape memory alloy restrainers have a very low probability of collapse (less than 7%). It is also found that the bridge retrofitted with Fe-based shape memory alloy restrainers (SMA-II and SMA-IV) performed better as compared to the other cases. Compared to the bridge without restrainers and with NiTi shape memory alloy restrainers, Fe-based shape memory alloy restrainers can reduce the long-term loss by about 87% and 11%, respectively, at the design earthquake event specified in CHBDC-2014. The probabilistic risk analysis of highway bridges retrofitted with shape memory alloy restrainers can aid in paving the way toward widespread application of such smart materials in structural applications.

Structure and mobility of martensite variant interfaces in a Cu-Zn-AI shape memory alloy

2003 ◽  
Vol 112 ◽  
pp. 519-522 ◽  
Author(s):  
W. Cai ◽  
J. X. Zhang ◽  
Y. F. Zheng ◽  
L. C. Zhao
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Martensite Variant
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