Stiffness Analysis of Large Scale Multistage Rubber Bearing used for Mass Dampers

摘要

Horizontal restoring force of a multistage rubber bearing is affected by bending stiffness of stabilizing plate with which element rubber bearings are piled up. Horizontal stiffness of a multistage rubber bearing using stabilizing plates with smaller bending stiffness is smaller than that using stabilizing plates with larger bending stiffness nevertheless using same element laminated rubber bearing under same vertical load. This phenomenon is caused by decreasing horizontal stiffness of element laminated rubber bearings because of rotation of upper and lower edges of element rubber bearing. This effects was confirmed by combined loading tests of element rubber bearings. To estimate horizontal stifiness of multistage rubber bearings with various bending stiffness of stabilizing plates, we propose an analytical model for element laminated rubber which could trace reduction of horizontal stiffness by increasing of rotation angle of element laminated rubber bearing. Estmated horizontal stiffness and deformation shape of multistage rubber bearing agreed with the experimental results.