缓冲型防落梁钢圈限位装置力学性能研究

Study on Mechanical Properties of a Steel Ring Anti-Fall Restrainer with Buffer Capacity

针对目前桥梁的限位装置缺乏缓冲能力的问题,提出一种缓冲型防落梁钢圈限位装置,采用Abaqus软件建立该钢圈限位装置的有限元模型,分析其在水平位移作用下的反力～位移曲线、应力分布和变形,并研究钢圈直线段长度、弧线段半径、截面直径和导向轮直径对其力学性能的影响。结果表明:加载初期,钢圈的限位作用未启动,当超过设定位移后,钢圈提供较小的初期刚度,之后随着位移的增加刚度快速增加,钢圈达到最大承载力后发生颈缩、断裂而破坏;钢圈启动限位装置时的位移、极限承载力、极限位移随钢圈直线段长度的增加而增加;钢圈的极限承载力、极限位移、初期刚度、二期刚度及缓冲能力随钢圈截面直径的增加显著提高;随着钢圈弧线段半径的增加,钢圈的缓冲能力及极限位移增加,初期限位刚度降低;随着导向轮直径的增加,钢圈的缓冲能力、二期限位刚度和极限承载力增加,极限位移减小。

In view of the problem that the restrainer of a bridge lacks buffer capacity,we proposed to install a steel ring anti-fall restrainer with buffer capacity.We established an FEM model of the steel ring restrainer by the software Abaqus,and analyzed the reaction force-displacement curve,stress distribution and deformation of the steel ring restrainer under monotonic horizontal displacement loading.Meanwhile,we studied the influences of the straight segment length,the arc segment radius,the diameter of the cross section and the guide wheel of the steel ring on mechanical properties of the steel ring.The results show that the steel ring restrainer is not activated in the initial loading stage.The steel ring provides a small initial stiffness when exceeding the set displacement,then the stiffness increases rapidly as the displacement increases.Constriction and fracture will occur when the steel ring restrainer reaches its ultimate strength.The starting displacement limit,ultimate strength and ultimate displacement of the steel ring will increase as the length of its straight segment increases;The ultimate strength,ultimate displacement,initial stiffness,second-stage stiffness and buffer capacity will increase significantly as the diameter of the steel ring increases.The buffer capacity and ultimate displacement of the steel ring restrainer will increase and the initial stiffness will decrease as the radius of the arc segment increases;the buffer capacity,the second-stage stiffness and ultimate strength of the steel ring will increase and the ultimate displacement will decrease as the diameter of the guide wheels increases.