新型桥梁“耗能限位”一体化弧形板装置力学性能试验及参数敏感性分

Experimental study and parametric sensitivity analysis on mechanical properties of a novel energy-dissipative-unseating-prevention arc-shaped plate device

为解决强震作用下中小跨径简支梁桥的落梁问题,研发了一种经济高效、安装便捷的新型“耗能限位”梁一体化弧形板装置.首先采用拟静力试验研究了不同截面的弧形板装置滞回耗能行为和疲劳破坏机理,接着采用数值分析的手段探讨了参数对装置力位移骨架曲线及等效阻尼比的影响规律,并补充了弧形板装置的防落梁行为模式与极限承载能力.结果表明:提出的新型弧形板装置具有优异的耗能能力,T形截面的弧形板结构更加合理,等效阻尼比最大能达到近40%;弧形板装置可通过分离几何参数对耗能能力、滞回强度、刚度及位移能力进行设计,增大中间截面的腹板高度h2是提高弧形板耗能能力的最有效手段,增加50%的h2能提高50.1%的最大强度与约4.7%的等效阻尼比.所提出的新型防落梁装置为桥梁中小震消能和强震柔性防落梁提供一体化装置解决方案.

To solve the problem of unseating of bridge spans in small-and-medium-span simple-supported girder bridges under strong earthquakes,a novel energy-consuming and easy-to-install integrated energy-dissipative-unseating-prevention arc-shaped plate device was developed.First,quasi-static tests were used to study the hysteretic energy dissipation behavior and fatigue failure mechanism of arc-shaped plate devices with different cross-sections.Then,numerical analysis was used to explore the influence of parameters on the skeleton curve and equivalent damping ratio of the device,and the unseating prevention behavior mode and ultimate capacity of the arc-shaped plate device were supplemented.The results show that the proposed new arc-shaped plate device has excellent energy dissipation capacity.T-shaped arc-shaped plate structure is more reasonable,and the equivalent damping ratio can reach a maximum of nearly 40%.The device can be designed by separating geometric parameters to design energy dissipation capacity,hysteretic strength,stiffness and displacement capacity.Increasing the web height h2 of the middle section is the most effective method to improve the energy dissipation capacity of the arc-shaped plate.Increasing h_(2)by 50%can increase the maximum strength by 50.1%and the equivalent damping ratio by about 4.7%.The proposed new unseating-prevention device can provide an integrated device solution for bridges with small-and-medium earthquake energy dissipation and strong earthquake flexible unseating-prevention.