Z24 bridge dynamic data analysis by time domain methods

Aim of this work is to compare the results obtained by applying two time domain techniques, namely the Ibrahim Time Domain (ITD) and the Auto Regressive Moving Average Vector (ARMAV) methods, to the acceleration data prepared for the benchmark on the Z24 bridge, located near Solothurn, CH. Both the ITD method, based on the analysis of the impulse response of a system, and the ARMAV model, well suited to the analysis of output only systems, are tested on the free vibration data, collected on the bridge after its impact with a falling mass. Special attention is devoted to eliminate computational modes, taking advantage from the fact that both the techniques can perform, on each measured time history, numerous evaluations of the modal parameters. The analyses have been carried out by means of a dedicated software, BnViD, specifically developed, in collaboration with Selpro SpA, in order to limit the user's personal choices during the data processing.