Cyclic behaviour evaluation of T-Joints for the seismic assessment of piping systems

The seismic performance of non-structural components is nowadays recognized to be a key issue in earthquake engineering, as demonstrated by the increasing number of studies on those elements whose failure could affect the immediate post earthquake functionality as well as the life safety. In fact, in case of Government buildings, the loss of operation of devices and piping systems, often implies hardships in local administration and economy; moreover, in strategic facilities as Hospitals and Schools, non-structural components play a key role in the post-earthquake emergency. The failure of fire-sprinkler and medical gas piping systems significantly affects the immediate functionality, which is very important to provide the first aid to the injure in the first hours after the earthquake. In this study, the seismic performance of piping systems has been investigated by experimental tests on cast iron and copper Tee-Joints. Quasi-static cyclic tests have been performed to identify the parameters influencing the behaviour of the components, which will be used to calibrate accurate FE model and simplified relationships to predict the hysteretic response of the jointed connection. The simplif ied macro-models, may be adopted for performance analysis of piping system layouts in public buildings, taking into account the nonlinear response of joints and necks, which are the weakest elements.