{"title":"Feasibility of using superelastic shape memory alloy in plastic hinge regions of steel bridge columns for seismic applications","authors":"Ahmad Rahmzadeh, M. Shahria Alam","doi":"10.1002/eqe.4150","DOIUrl":null,"url":null,"abstract":"<p>This paper contributes to the further development of seismic resilient infrastructure by introducing a novel prototype bridge which integrates tubular steel piers with superelastic shape memory alloy (SMA). The proposed bridge pier is composed of a circular steel tube which is bonded to a superelastic SMA tube in regions of high stress. The pier is distinguished by its ability to minimize residual drifts following inelastic deformations induced by cyclic loading. Three-dimensional continuum finite element (FE) models are utilized to examine its lateral behavior. Experimental data is used to demonstrate the effectiveness of the continuum FE procedure in replicating the cyclic response and capturing both global and localized behaviors. A novel composite material model is proposed to represent the degradation of strength and accumulation of irreversible strains in the cyclic response of superelastic SMAs. An iterative procedure for the calibration of this material is presented. Investigations, employing the calibrated FE procedure, focus on the quasi-static cyclic response of steel piers with superelastic SMA in the plastic hinge zone, aiming to identify the optimal length of the SMA tube for achieving a self-centering response with reduced residual deformation. The study is then further expanded to examine the seismic response of a bridge structure incorporating such piers. Development of the FE model for the prototype bridge includes the modelling of the piers using continuum elements, while the superstructure, bearing units, abutment walls, and backfill material are modelled using discrete elements. Nonlinear time history analyses are undertaken to investigate the effects of column wall thickness and materials used in the plastic hinge zones of the piers. Dynamic FE study results indicate that bridges employing such piers are capable of returning to their original position, provided the SMA tube is of adequate length.</p>","PeriodicalId":11390,"journal":{"name":"Earthquake Engineering & Structural Dynamics","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/eqe.4150","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earthquake Engineering & Structural Dynamics","FirstCategoryId":"5","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/eqe.4150","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 0
Abstract
This paper contributes to the further development of seismic resilient infrastructure by introducing a novel prototype bridge which integrates tubular steel piers with superelastic shape memory alloy (SMA). The proposed bridge pier is composed of a circular steel tube which is bonded to a superelastic SMA tube in regions of high stress. The pier is distinguished by its ability to minimize residual drifts following inelastic deformations induced by cyclic loading. Three-dimensional continuum finite element (FE) models are utilized to examine its lateral behavior. Experimental data is used to demonstrate the effectiveness of the continuum FE procedure in replicating the cyclic response and capturing both global and localized behaviors. A novel composite material model is proposed to represent the degradation of strength and accumulation of irreversible strains in the cyclic response of superelastic SMAs. An iterative procedure for the calibration of this material is presented. Investigations, employing the calibrated FE procedure, focus on the quasi-static cyclic response of steel piers with superelastic SMA in the plastic hinge zone, aiming to identify the optimal length of the SMA tube for achieving a self-centering response with reduced residual deformation. The study is then further expanded to examine the seismic response of a bridge structure incorporating such piers. Development of the FE model for the prototype bridge includes the modelling of the piers using continuum elements, while the superstructure, bearing units, abutment walls, and backfill material are modelled using discrete elements. Nonlinear time history analyses are undertaken to investigate the effects of column wall thickness and materials used in the plastic hinge zones of the piers. Dynamic FE study results indicate that bridges employing such piers are capable of returning to their original position, provided the SMA tube is of adequate length.
本文介绍了一种新型原型桥梁,它将管状钢墩与超弹性形状记忆合金(SMA)融为一体,为进一步开发抗震基础设施做出了贡献。拟议的桥墩由圆形钢管组成,钢管在高应力区域与超弹性 SMA 管粘接。该桥墩的特点是能够最大限度地减少循环加载引起的非弹性变形后的残余漂移。三维连续有限元(FE)模型用于研究其横向行为。实验数据用于证明连续有限元程序在复制循环响应以及捕捉整体和局部行为方面的有效性。提出了一种新型复合材料模型,用于表示超弹性 SMA 循环响应中的强度退化和不可逆应变累积。此外,还介绍了校准该材料的迭代程序。采用校准 FE 程序的研究重点是塑性铰区超弹性 SMA 钢墩的准静态循环响应,旨在确定 SMA 管的最佳长度,以实现自定心响应并减少残余变形。随后,研究进一步扩展,以检验包含此类桥墩的桥梁结构的地震响应。原型桥梁有限元模型的开发包括使用连续单元对桥墩进行建模,而上部结构、承重单元、桥墩墙和回填材料则使用离散单元建模。进行了非线性时间历程分析,以研究柱壁厚度和桥墩塑性铰区所用材料的影响。动态 FE 研究结果表明,只要 SMA 管的长度足够长,采用这种桥墩的桥梁就能恢复到原来的位置。
期刊介绍:
Earthquake Engineering and Structural Dynamics provides a forum for the publication of papers on several aspects of engineering related to earthquakes. The problems in this field, and their solutions, are international in character and require knowledge of several traditional disciplines; the Journal will reflect this. Papers that may be relevant but do not emphasize earthquake engineering and related structural dynamics are not suitable for the Journal. Relevant topics include the following:
ground motions for analysis and design
geotechnical earthquake engineering
probabilistic and deterministic methods of dynamic analysis
experimental behaviour of structures
seismic protective systems
system identification
risk assessment
seismic code requirements
methods for earthquake-resistant design and retrofit of structures.