Experimental Research On Mechanical Properties Of Lead Rubber Bearing Under Multiaxial Load

With the sustainable development of economy and urbanization process, base isolation technology has gradually been applied in high-rise buildings and large span space structures. Currently, the lead rubber bearing has been widely used in practical engineering, and shows good isolation effect in actual earthquake. In recent studies related to the mechanical properties of bearings, experimental and theoretical analysis were conducted under the unidirectional horizontal deformation with constant vertical load, but in actual earthquake, lead rubber bearing is in a multiaxial load state, the horizontal bidirectional load and vertical load will have an impact on the mechanical property of bearing, therefore, it is necessary to study the mechanical property of lead rubber bearing under multiaxial load state.In view of the preceding problem, this paper studied the mechanical properties of a lead rubber bearing with a diameter of 200 mm under multiaxial load state through test. The main research content is as follow:(1) Horizontal unidirectional test was conducted to study the influence of vertical load and shear strain on equivalent stiffness, equivalent damping ratio, post-yield stiffness and yield strength of bearing.(2) Horizontal bidirectional test was conducted to study the influence of vertical load and shear strain on equivalent stiffness, equivalent damping ratio, post-yield stiffness and yield strength of bearing both in X and Y direction. In addition, the influence of coupling effect on mechanical properties of bearing was studied through comparing the result with horizontal unidirectional test.(3) Horizontal bidirectional eight shaped test was conducted to study the influence of vertical load and shear strain on equivalent stiffness, equivalent damping ratio, post-yield stiffness and yield strength of bearing both in X and Y direction, analysis the change regularity of horizontal mechanics performance of X direction of bearing with the shear strain. Moreover, the influence of shear strain in Y direction on mechanical properties of bearing in X direction was analyzed.