Response Performance Characteristics of LRB Base Isolator for Cyclotron Building Due to Parts Sizing

Study of the effects of part sizing on Lead Rubber Bearing Base (LRB) isolator for cyclotron building foundation application has been carried out. The cyclotron building design must be able to withstand earthquake loads without damaging either the structural integrity or the functionality of the building as the shielding against the radiation rays generated when the cyclotron operates. Lead Rubber Bearing (LRB) base isolators are designed for the cyclotron building foundation to provide structural integrity and reliability against earthquakes. The LRB base isolator constructed as a stack of flat rubber and steel ring plates with lead in the center. Variation of the sizes of the LRB parts are bringing up the necessity to investigate further the response characteristics of the cyclotron building due to an earthquake excitation. Parts sizing of the LRB are of the steel plates thickness, the rubber layer thickness as well as the diameter of the leads. From the simulation then it is revealed that every configuration size is giving different effective stiffness, vertical stiffness as well as damping values in vibration isolation percentage value. Results from an LRB static analysis then are included as well in the dynamic analysis to determine differences in cyclotron building responses. The computer FEA simulation running on Abaqus and Solid Work® 3D FEM software platform revealed that changes in the thickness of the plate, rubber layer and lead diameter affected the dynamic responses of the cyclotron buildings when subjected to earthquake loads.