To prevent unseating failures and pounding problems in simply supported bridges, steel restrainers that can limit relative displacements of adjacent spans have commonly been used. This study proposes a shape memory alloy (SMA)-based restrainer that can serve as both energy dissipater and restrainer under cyclic tension and compression loading. The proposed device named as, long-stroke SMA restrainer (LSR), consists of a superelastic SMA bar, a steel tube, and a filler material. The SMA bar provides re-centering force and dissipates energy, while steel tube and the infill material prevent buckling of SMA bar under compression. Taking advantages of large strain capacity of SMAs, the LSRs are designed to accommodate large displacement demands for bridge restrainers. The mechanical response of NiTi SMA bars with a diameter of 12 mm was first studied through uniaxial tension and compression testing. Buckling and post-buckling response of the SMA bars were also characterized. Then, a ...

中文翻译：

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用于桥梁抗震保护的长冲程形状记忆合金约束器

为了防止在简单支撑的桥梁中发生座落故障和撞击问题，通常使用可以限制相邻跨度的相对位移的钢制约束器。这项研究提出了一种基于形状记忆合金（SMA）的约束器，该约束器在循环拉伸和压缩载荷下既可以用作耗能器，又可以用作约束器。拟议中的装置称为长冲程SMA限位器（LSR），它由超弹性SMA棒，钢管和填充材料组成。SMA棒提供重新定心力并耗散能量，而钢管和填充材料可防止SMA棒在压缩状态下弯曲。利用SMA的大应变能力，LSR设计用于满足桥梁限制器的大位移需求。首先通过单轴拉伸和压缩测试研究了直径为12 mm的NiTi SMA棒的机械响应。还对SMA条的屈曲和屈曲后响应进行了表征。然后，...