DESIGN , MANUFACTURING AND EVALUATION OF THE PERFORMANCE OF FIBER REINFORCED ELASTOMERIC SEISMIC ISOLATORS

In this paper, the performance of multi-layer elastomeric seismic isolators, which have been reinforced by layers of woven carbon fibers, is studied. Specimens of this kind of isolators as well as a specimen of similar size and shape reinforced by steel plates have been designed and manufactured. They have then been tested under cyclic vertical and horizontal loads to determine their dynamic and mechanical properties and performance. Design of the steel reinforced specimen has been carried out according to current method of design of isolators. For the fiber reinforced isolators the same method has been applied taking into consideration the tensile and bending flexibility of the fiber cords. Results of the experiments show that the behavior of the fiber reinforced elastomeric isolators is very similar to that of the steel reinforced specimen with regard to shear deformation and dynamic and mechanical characteristics including vertical stiffness, effective horizontal stiffness and damping. Therefore, this type of fiber reinforced isolator which has been named "steel like fiber reinforced elastomeric isolators" (SLFREI), can be used in seismic isolation of structures. The advantages of SLFREI are that they are lighter and simpler to manufacture compared to steel reinforced elastomeric isolators. The main differences between SLFREI and fiber reinforced elastomeric isolators, previously reported in the literature, are hat the frictional damping is not produced in reinforcement fibers of the SLFREI and it has been able to sustain very large shear strains (225%) in the presence of top and bottom steel end plates.