Comparative Analysis of SIVC Systems Using Simplified Analytical Modeling for Practical Design

Abstract

Past research has revealed that a sliding isolator with variable curvature (SIVC) can alleviate the resonance phenomenon that is likely to occur in a conventional friction pendulum system (FPS) due to its constant isolation frequency. Despite that, the use of SIVC systems is restricted to research purposes due to the nonavailability of a convenient modeling and analysis approach. The present study proposes a universal simplified modeling and analysis approach using the finite-element analysis software SAP2000, which can effectively simulate the behavior of four well known SIVC systems. Selecting the frequency variation parameters (FVPs), the effect of FVPs on the performance structures isolated by a variable frequency pendulum isolator (VFPI), variable curvature friction pendulum system (VCFPS), conical friction pendulum isolator (CFPI), and polynomial friction pendulum isolator (PFPI) have been studied under varied ground excitation by using the proposed modeling approach. Afterward, these chosen FVPs have been used to compare the effectiveness of SIVC systems under varied ground excitations for isolator parameters. The results indicate that VFPI more effectively controls the structural response than other SIVC systems, but it may show excessive sliding displacement for earthquakes having 4–6 s time-period long waves. Whereas in these types of earthquakes, CFPI and PFPI can effectively control the sliding displacement, but VCFPS fails to serve its design purpose for other earthquakes. The overall behavior of a structure isolated by VFPI remains more effective than one isolated by other SIVC systems for a wide range of earthquakes, especially for those earthquakes that have 0.1–4 s time-period waves.