INFLUENCE OF FRICTION MODELS ON RESPONSE EVALUATION OFBUILDINGS WITH SLIDING ISOLATION DEVICES

摘要

The application of base isolation systems with energy dissipation for aseismic design of building is wellestablished and has been implemented for a large number of buildings. Friction provides excellentmechanism for energy dissipation at the sliding surface. A wide variety of isolation devices using frictionfor dissipation of energy have been proposed. Their design requires numerical simulations that commonlymodel hysteretic behavior of friction dampers using Coulomb friction, where the coefficient of friction isconstant. However, the basic laws for typical sliding materials and experimental investigations showcomplex behavior of friction force, in both sliding and transition phases, that include the non-linearrelationship between friction and sliding velocity, and the effect of time history of response, stiction andsliding velocity. This paper investigates the behavior of framed structures with sliding isolation systemssubjected to earthquake ground motions. The paper considers Coulomb friction model as well as othermore complex models to assess the response of structures with sliding isolation systems. The analysisresults show that stiction and Stribeck effect, which are often not considered in the design of buildingswith friction based isolation systems, significantly influence the isolator behavior. It is concluded thatsimplified analysis using Coulomb friction model may significantly overestimate the effectiveness ofsliding isolation devices.