Simulation issues with a real-time, full-scale seismic testing system

Large seismic isolation bearings and/or dampers are currently used to seismically retrofit several long-span bridges. These large devices must be thoroughly tested at full-scale with real-time seismic demands, necessitating new, larger seismic testing facilities. Accurate performance characterisation of these devices depends on thorough characterisation of the seismic testing facility itself. One component of this essential systems' characterisation is a mathematical simulation model. Although linear modelling techniques have traditionally been used to characterise seismic facilities, many of the large system's unique behaviours, parameters and non-linearities significantly reduce the accuracy of linear modelling techniques. These significant characteristics are discussed in detail. A more comprehensive non-linear modelling approach is required for these large facilities, and a simulation model using a non-linear time-history dynamic analysis approach is outlined.