Utilizing a new self-centering hysteresis model to assess the seismic vulnerability of a long-span cable-stayed bridge equipped with SMA wire-based roller bearings.
Utilizing a new self-centering hysteresis model to assess the seismic vulnerability of a long-span cable-stayed bridge equipped with SMA wire-based roller bearings.
复制标题
利用新的自定心磁滞模型评估配备 SMA 线基滚子轴承的大跨度斜拉桥的地震脆弱性
DOI：
10.1186/s43251-022-00064-z
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
中科院分区：
文献类型：
--
作者：
研制了一种新型形状记忆合金丝基智能滚子轴承（SMA-RBs），并对其在反复循环载荷下的循环特性进行了实验研究。然而，其在提高桥梁结构抗震性能方面的功效和性能尚未得到很好的理解和证明。提出了一种新的自对中滞回模型，并通过拟静力试验验证了该模型的正确性。提出了一种方法来确定四个损伤状态的SMA-RB（即轻微，中度，广泛，崩溃）考虑SMA线的贡献。智能SMA-RBs应用于中国某斜拉桥。从构件和系统两个层面对两座参考桥梁（浮式体系（FS）和刚性体系（RS））以及一座配备SMA-RBS的孤立桥梁（SMA-RBS）的脆弱性进行了比较。对PGA、PGV和Sa（T1）三种常用强度指标的适用性进行了评价，结果表明PGV是大跨度斜拉桥体系的最优强度指标。结果表明，在滚动轴承中加入SMA丝可以降低轴承的失效概率。与参考桥梁中的塔和墩相比，具有SMA-RB的墩和塔导致较低的地震易损性。RS是最脆弱的网桥，而SMA-RBS是四个网桥中最不脆弱的网桥。与RS和FS相比，SMA-RBS的倒塌损坏概率要低得多。
A novel shape memory alloy wires-based smart roller bearing (SMA-RBs) has been developed and its cyclic behavior under reverse cyclic loadings has been experimentally investigated. However, its efficacy and performance in enhancing the seismic performance of bridge structures have not been well understood and proven. A new self-centering hysteresis model for SMA-RBs has been proposed to properly simulate their hysteretic behavior, which has been experimentally validated through a pseudo-static test. A methodology is proposed to determine the four damage states of SMA-RB (i.e. slight, moderate, extensive, and collapse) considering the contribution of SMA wires. The smart SMA-RBs are utilized for a cable-stayed bridge in China. The vulnerability of two reference bridges, i.e. the floating system (FS) and rigid system (RS), and one isolated bridge equipped with SMA-RBs (SMA-RBS) are compared at component and system levels. The applicability of three commonly used intensity measures (IMs), i.e. PGA, PGV, and Sa(T1), are evaluated and PGV turns out to be the optimal IM for long-span cable-stayed bridge systems. Results show that incorporating SMA wires in roller bearings can decrease the failure probabilities of the bearing. The piers and towers with SMA-RBs lead to lower seismic fragility over the towers and piers in the reference bridges. The RS is the most vulnerable bridge whereas the SMA-RBS is the least vulnerable bridge among the four bridges. The SMA-RBS experience a much lower collapse damage probability compared to RS ad FS.