Testing and modeling of square carbon fiber-reinforced elastomeric seismic isolators

Steel-reinforced elastomeric isolators (SREIs), as an effective seismic isolation device, are the most common isolators in use. However, SREIs are typically heavy and expensive and, as a result, application of these devices is often limited to large and expensive structures. A reduction in the cost and weight of elastomeric isolators would permit a significant increase in their application to many ordinary residential and commercial buildings. Fiber-reinforced elastomeric isolators (FREIs) are a new type of elastomeric bearing that employs fiber as the reinforcement material rather than steel. FREIs have several advantages over traditional SREIs including superior damping properties, lower manufacturing cost, light weight, and the possibility of being produced in long rectangular strips with individual isolators cut to the required size. This paper presents a brief literature review on experiments with FREIs, and reports on an experimental study conducted on carbon FREIs from which the mechanical properties of the bearings, including displacement characteristics and damping values are evaluated. A brief description of an analytical approach to model the cyclic response of the bearings is another component of this paper. As a special application, the bearings considered in this study were not bonded to the test platens. For bearings having suitable aspect ratio values, this particular type of application resulted in a stable rollover deformation, which reduced the horizontal stiffness and increased the efficiency of the bearing as a seismic isolator device. Test results suggest that for many high seismic risk regions worldwide, the application considered in this study can be viable for the base isolation of ordinary low-rise buildings. Copyright (C) 2007 John Wiley & Sons, Ltd.