缓冲型防落梁钢圈限位装置力学性能试验

经合理设计的防落梁限位装置可以有效减小地震发生时桥梁上、下部结构间的相对位移,阻止落梁破坏的发生,而明确限位装置力学性能是对其进行合理设计的必要前提.为探明缓冲型防落梁钢圈限位装置的滞回性能和破坏模式,并提出极限位移和极限承载力的计算方法,制作了6个试件进行拟静力试验研究.分析了钢材种类、限位装置截面高度h和直线段长度...

Experimental Study on Mechanical Properties of Steel Ring Restrainers with Buffer Capacity

Reasonably designed restrainers can effectively reduce the relative displacement between superstructures and substructures of bridges during earthquakes,and prevent the occurrence of unseating damage.The verified mechanical properties of restrainers are a necessary prerequisite for their reasonable design.Quasi-static tests were carried out on six manufactured specimens to study the hysteretic behavior and failure mode of a new type of steel ring restrainer with buffer capacity,and establish a method for calculating the ultimate displacement and ultimate bearing capacity.In this study,the influences of design parameters such as the type of steel,section height h,and straight length aon the mechanical properties are evaluated.According to the results,it was deduced that:①during the initial loading and unloading process,the specimens are mainly governed by bending deformation,whereas the effects of the stiffness and force are minor.Because of the early occurrence of plasticity of the arc segment,unrecoverable deformation occurs after unloading.The accumulative plastic deformation is increased during the repeated loading process.In the later stage of loading,the deformation of the specimens is mainly because of tension,and a large stiffness is observed.Necking appears and a fracture occurs after the ultimate bearing capacity;②for the strain measured at the arc segment of the specimens during the initial loading,the inside and outside surfaces of the section are in tension and compression,respectively.With the increase in displacement,the specimen is straightened and the neutral axis is off-center of the section after the outside section reaches the maximum compressive strain.When failure occurs,high tensile strain occurs in all parts of the test specimen;③ahas a significant effect on the start-restraint displacement,but the effect of the initial stiffness is slight.When hincreases,the growth rate of the force,initial stiffness,and ultimate bearing capacity increase;however,the effect on the displacement is small.The type of steel has a significant effect on the bearing capacity of the specimen but has little effect on the displacement.Formulas for calculating the ultimate bearing capacity and displacement are proposed based on the experimental results,and their accuracy is verified.