基于应力幅差的非对称吊杆破损安全性能分析

Safety performance analysis of asymmetric suspender damage based on the different amplitude of stress

为了提高拱桥吊杆的安全性能,基于破损安全双吊杆理论(即对双吊杆采用不同面积比,并设定截面积较小的为主承重吊杆F杆,截面积较大的为安全吊杆S杆),提出一种通过改变双吊杆应力幅差从而实现吊杆先、后破坏断裂的设计方法(即在S杆下方增设不同刚度的橡胶垫块)。以云南省某下承式拱桥为例,通过有限元软件,模拟分析双吊杆在不同的面积比和橡胶垫块刚度下该设计方法是否能达到破损安全的目的。研究结果表明:该设计方法有效。适当增加S杆的面积比,有利于F杆破断瞬间S杆的安全性;且合理地调整与S杆串联的橡胶垫块的刚度,有利于提高吊杆的破损安全性能。

In order to improve the safety performance of the suspenders of arch bridges,based on the theory of double suspenders for damaged safety(adopting different area ratio for double suspenders,and setting the smaller section area as F-bar and the larger as S-bar),a design method was proposed to achieve the successive failure and fracture of suspenders by changing the stress amplitude difference of double suspenders(adding rubber cushion blocks with different rigidity under S-bar).Taking a through arch bridge in Yunnan Province as an example,it was analyzed whether the goal of damage safety can beachieve using this design method under different area ratio and rubber pad stiffness by the finite element software simulation.The results show that the design method is effective,and properly increasing the area ratio of the S-bar is conducive to the safety of the S-bar at the moment of breaking of the F-bar,and reasonably adjusting the rigidity of the rubber cushion block in series with the S-bar is conducive to improving the safety performance of the damaged safety suspender.