PEER has just published Report No. 2015/03 titled “Single Series Solution for the Rectangular Fiber-Reinforced Elastomeric Isolator Compression Modulus” as a new addition to the PEER Report Series. It was authored by James M. Kelly and Niel C. Van Engelen.
Fiber-reinforced elastomeric bearings were originally proposed as an alternative to conventional steel-reinforced elastomeric bearings for seismic isolation applications. The flexible fiber reinforcement is a light-weight and potentially cost-saving alternative to steel reinforcement, which is assumed rigid in the design process. The variety of fiber materials available also serves as an additional parameter for designers to tailor the vertical stiffness of the bearing. In this report, a further cost reduction is visualized by manufacturing the bearing in a large sheet that can be cut to the required size such that the ideal shape for the bearing will be rectangular. An analytical solution for the vertical compression modulus of a rectangular elastomeric pad including the effects of the elastomer bulk compressibility and extensibility of the fiber reinforcement is given here in the form of a rapidly convergent single series. This solution is computationally efficient and allows for a rapid calculation of the stiffness for both design and analysis purposes.