EACS 2016 paper - A comparison of online and offline experimental substructuring methods for the simulation of complex linear dynamic systems

<p>EACS 2016 Paper No. 122</p><p>Online hybrid (numerical/physical) dynamic substructuring simulations (HDS) on an as-built/isolated viaduct and on a petrochemical piping subject to non-stationary seismic loading have shown their potential for efficient realistic dynamic analysis of almost any type of structural system. Moreover, owing to ever faster and more accurate testing equipment, dynamic substructure coupling developed in mechanical engineering through a number of different offline experimental substructuring methods operating both in time, e.g. the impulse-based substructuring (IBS), and frequency domains. Numerous studies have dealt with the above-mentioned methods and with associated error/uncertainty propagations issues. Nonetheless, there is still a paucity of publications devoted to: i) the comparison of the performances of these methods from an error/uncertainty perspective; ii) the possibility of their exploitation in a complementary way to both improve and speed up the overall experiment/simulation. In this paper, we compare the performances of these methods including standard time integration schemes and the coupling algorithm of subdomains based on an advanced parallel finite element tearing interconnecting algorithm. Moreover, we include typical random uncertainties coming from devices and operators exploited in the analysed methods. Main results and comparisons based on Monte Carlo sampling of three- and five-DoF linear systems point out that the HDS method exhibits better performances with respect to phase and energy errors whilst the IBS slightly prevails on coefficients of variation of coupling node displacements.</p>