In general, shape memory alloy (SMA) cables do not resist in compression and, thus, their applications are limited. This study suggests a superelastic SMA bar in bending to be used to overcome the above problem. The objectives of this study are to analyze the characteristics of the bending behavior of an SMA bar and to prove its seismic applicability, especially to restrain openings in bridges. Single and double bending tests are conducted with varying loading speeds and maximum displacements. The loading and the unloading stiffness are estimated from the force-displacement curves, and the equivalent damping ratio of each test is assessed. The SMA bar shows the same stiffness hardening, during bending and under tension which appears to be due to stress-induced-martensite hardening. Increasing the loading speed does not influence the stiffness of the SMA bar with a single bend, but the stiffness of the double bending bar is about five times that of the single bending bar. This study also introduces the use of SMA bending bars as a seismic restrainer for bridges. The SMA bars are assessed as seismic restrainers for a three-span-simply-supported bridge in a zone of moderate seismic activity. The bars reduce the openings at the internal hinges and the pounding force on abutments. Thus, the SMA bending bars are assessed to prevent the unseating at internal hinges and cracks on abutments. This study shows the applicability of the SMA bending bars as a seismic restrainer.

中文翻译：

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形状记忆合金弯杆作为地震地区桥梁的减震器

通常，形状记忆合金（SMA）电缆不能抗压，因此其应用受到限制。这项研究提出了一种弯曲的超弹性SMA钢筋，可以用来克服上述问题。这项研究的目的是分析SMA钢筋的弯曲行为特征，并证明其抗震性，尤其是限制桥梁的开口。在不同的加载速度和最大位移下进行单次和两次弯曲测试。根据力-位移曲线估算载荷和卸载刚度，并评估每个测试的等效阻尼比。SMA棒在弯曲期间和张力下显示出相同的刚度硬化，这似乎是由于应力诱导的马氏体硬化所致。增加加载速度不会影响单弯曲的SMA杆的刚度，但双弯曲的杆的刚度约为单弯曲的杆的五倍。这项研究还介绍了使用SMA弯曲杆作为桥梁的减震器。SMA钢筋被评估为中等地震活动区内三跨简单支撑桥梁的地震约束。杆减少了内部铰链上的开口以及对基台的撞击力。因此，对SMA弯曲杆进行了评估，以防止内部铰链处的咬合和基台上的裂纹。这项研究表明SMA弯曲杆作为抗震器的适用性。这项研究还介绍了使用SMA弯曲杆作为桥梁的减震器。SMA钢筋被评估为中等地震活动区内三跨简单支撑桥梁的地震约束。杆减少了内部铰链处的开口以及对基台的撞击力。因此，对SMA弯曲杆进行了评估，以防止内部铰链处的咬合和基台上的裂纹。这项研究表明SMA弯曲杆作为抗震器的适用性。这项研究还介绍了使用SMA弯曲杆作为桥梁的减震器。SMA钢筋被评估为中等地震活动区内三跨简单支撑桥梁的地震约束。杆减少了内部铰链上的开口以及对基台的撞击力。因此，对SMA弯曲杆进行了评估，以防止内部铰链处的咬合和基台上的裂纹。这项研究表明SMA弯曲杆作为抗震器的适用性。对SMA弯曲杆进行了评估，以防止内部铰链松动并防止基台开裂。这项研究表明了SMA弯曲杆作为抗震器的适用性。对SMA弯曲杆进行了评估，以防止内部铰链松动并防止基台开裂。这项研究表明SMA弯曲杆作为抗震器的适用性。