Stability Analysis of Real Time Substructuring on Strong Nonlinear Dampers

Rate-dependent effects are very significant when evaluating the behaviour of energy dissipation devices in seismic protection systems. Real-Time Dynamic Substructuring Test (RTDS) is a novel and rather valuable dynamical testing method in earthquake engineering, it allows the assessment of dynamic behaviour in nonlinear range under extreme loading conditions. In RTDS, the system is divided into two substructures: a physical and a numerical part. To accurately represent the original system, these two parts must operate in parallel with minimal errors at the interfaces between them. It is known that delay errors at the interface are unavoidable and may cause instability in the simulation. In this paper, a stability analysis of a RTDS test which considers a strong nonlinear viscous fluid passive damper for civil engineering applications is presented. This analysis is addressed in the context of the qualitative theory of Piecewise Smooth Dynamical Systems. Numerical simulations are presented to confirm the analytical results.