形状记忆合金橡胶对高架桥梁碰撞减震效果的试验研究

地震作用下,高架桥梁相邻主梁间的碰撞会引起结构位移和加速度响应增大、应力提高,导致混凝土开裂、脱落和伸缩缝被挤压破坏,甚至引发桥梁落梁和倒塌等,因此采取减轻或者避免桥梁结构在地震作用下碰撞的措施显得尤为必要。设计制备了具有变形自恢复能力的形状记忆合金橡胶碰撞缓冲器,通过桥梁地震碰撞的振动台试验,研究了形状记忆合金橡胶缓冲器对桥梁碰撞的控制效果,提出了碰撞缓冲器吸能效率和结构自身耗能控制率指标。研究表明,形状记忆合金橡胶碰撞缓冲器具有稳定的吸能效率,能够大幅度降低桥梁结构碰撞加速度和碰撞力,这对于提高城市交通网络的地震安全性能具有重要意义。

Experimental Study on Pounding Mitigation of Highway Bridges with Shape Memory Alloy Pseudo-rubber

Structural pounding will enhance the response of acceleration and displacement under earthquake excitations. The increase of stress may lead to concrete cracking,expansion joint damage and even bridges collapse. Therefore,pounding mitigation measures for highway bridges are necessary. In this study,a kind of novel shock absorber made of shape memory alloy pseudo-rubber（ SMAPR-SAD） is presented,and the control effect of SMAPR-SADs on bridge pounding is investigated through shaking table test. The indexes representing energy absorption and dissipation of SMAPR-SAD during bridge pounding are also proposed. Results show that SMAPR-SAD has stable energy dissipation ratio and can greatly reduce the pounding acceleration and pounding force,which is of important significance to the structural performance of city transport network during earthquakes.