9. Hybrid Simulations of a Piping System Based on Model Reduction Techniques

The deficiency of seismic design standards for piping systems, their components and support structures necessitates experimental investigations of such structures under earthquake loading to extract valuable information for the amendments/development of relevant design guidelines. This paper describes an experimental test campaign carried out at the University of Trento, Italy, on a full-scale piping system in order to evaluate its seismic performance. In particular, a typical industrial piping system containing several critical components, such as elbows, a bolted flange joint and a Tee joint, was tested under different levels of earthquake loading corresponding to serviceability and ultimate limit states suggested by performance-based earthquake engineering standards. Hybrid Simulations with Dynamic Substructuring (HSDS) in both pseudo- and real-time were adopted to conduct seismic tests. Experimental results displayed a favorable performance of the piping system and its components; they remained below their yield limits without any leakage even for the Collapse Limit State. As a result, the proposed model reduction techniques were fully justified.