Lateral hysteretic behavior of a novel metal rubber bridge bearing
Lateral hysteretic behavior of a novel metal rubber bridge bearing
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DOI：
10.1016/j.engstruct.2022.114051
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发表时间：
2022-04
影响因子：
5.5
通讯作者：
X. Xia;Suiwen Wu;Senlin Sun;Q. Du;Fengxiang Long
中科院分区：
文献类型：
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作者：
X. Xia;Suiwen Wu;Senlin Sun;Q. Du;Fengxiang Long
针对传统橡胶支座存在的化学降解和腐蚀等老化问题，提出了一种新型金属橡胶支座，以替代传统橡胶支座应用于中小跨径公路桥梁。该轴承是由多孔金属丝通过卷绕、编织和冷压成特定形状而制成的。然后描述了两个不同密度的不锈钢丝金属橡胶支座的剪切试验程序，以确定滞回曲线的特征。研究了剪应变、压应力、加载频率和反复加载次数对试件滞回性能的影响。试验结果表明，试件的侧向滞回曲线近似为双线性，由初始弹性阶段和屈服后阶段组成。在25%剪应变水平下，试验支座的等效阻尼比约为20%，并随应变水平的增加而增大，具有一定的耗能能力。此外，由于钢丝分层和轴承鼓包引起的塑性变形，在超过一定变形极限的滞回曲线上观察到刚度退化。然而，超过这个极限，轴承仍然可以作为一个单元工作，具有稳定的滞后行为。这些特点使金属橡胶支座成为传统橡胶支座的一个很好的选择。试验结果还表明，混凝土的滞回性能与密度、加载频率和压应力等参数有关。最后，它被发现，Bouc-Wen模型与适当的输入参数表示的力学性能可以准确地模拟滞回曲线的建议轴承。
In this paper, a novel metal rubber bearing is proposed as an alternative to the conventional rubber bearings for small- and medium-span highway bridges to solve the aging-related issues of conventional rubber bearings such as chemical degradation and erosion. The bearing is made of porous metal wire by coiling, weaving and cold-pressing to specific shapes. A shear test program is then described on two metal rubber bearings of stainless steel wire with different densities in order to identify the characteristics of hysteretic curves. The effects of shear strain, compressive stress, loading frequency and repeated loading cycles on the hysteretic behavior were investigated. It was found that the lateral hysteretic curves are approximately in bilinear shape, which consists of an initial elastic stage and a post-yield stage. The equivalent damping ratio of the tested bearings was around 20% at 25% shear strain levels and meanwhile increased with the strain levels, indicating an appreciable energy dissipation capacity. In addition, stiffness degradation was observed for the hysteretic curves beyond a certain deformation limit due to the plastic deformation caused by wire delamination and bearing bulging. However, beyond this limit, the bearing could still work as a unit with stable hysteretic behavior. These characteristics make the metal rubber bearing a great candidate for the conventional rubber bearings. It was also found that the hysteretic behavior is related with a variety of parameters such as density, loading frequency and compressive stress. Finally, it was found that the Bouc-Wen model with appropriate input parameters representing the mechanical properties can accurately simulate the hysteretic curves of the proposed bearings.