The increasing number of studies dealing with the seismic vulnerability of piping systems underlines the importance of this item in the field of seismic engineering. An accurate prediction of the dynamic response of piping networks requires the definition of the non-linear behaviour of the weakest elements of the system which are usually damaged in case of earthquake. Several studies demonstrated that the pipe joints, as well as the connections with the supporting system, are the most vulnerable elements and require a particular deal of attention. Therefore, the present study deals with the nonlinear response of threaded tee-joints usually adopted in sprinkler piping systems. A numerical meso-model is developed in ANSYS platform, it is calibrated considering the stress distribution along the threaded interface between pipe and joint. A simplified geometry of the interface is developed, featuring an equivalent thread aimed at reproducing the effect of cyclic loading to the joint, with a particular focus on the simulation of the pinching effect. The prediction capability of the proposed model is verified through the experimental data available in the literature. Different material properties and pipe diameters have been taken into account. The accurate prediction of the nonlinear response of jointed connections is useful to conduct nonlinear time-history analysis of piping layouts and to simulate the energy dissipated by the system as well as to more accurately evaluate its seismic vulnerability.
Numerical modelling of the cyclic response of threaded joints for the seismic behaviour evaluation of piping systems
Blasi, Gianni;Perrone, Daniele;Aiello, Maria Antonietta;Pecce, Maria Rosaria
2019-01-01
Abstract
The increasing number of studies dealing with the seismic vulnerability of piping systems underlines the importance of this item in the field of seismic engineering. An accurate prediction of the dynamic response of piping networks requires the definition of the non-linear behaviour of the weakest elements of the system which are usually damaged in case of earthquake. Several studies demonstrated that the pipe joints, as well as the connections with the supporting system, are the most vulnerable elements and require a particular deal of attention. Therefore, the present study deals with the nonlinear response of threaded tee-joints usually adopted in sprinkler piping systems. A numerical meso-model is developed in ANSYS platform, it is calibrated considering the stress distribution along the threaded interface between pipe and joint. A simplified geometry of the interface is developed, featuring an equivalent thread aimed at reproducing the effect of cyclic loading to the joint, with a particular focus on the simulation of the pinching effect. The prediction capability of the proposed model is verified through the experimental data available in the literature. Different material properties and pipe diameters have been taken into account. The accurate prediction of the nonlinear response of jointed connections is useful to conduct nonlinear time-history analysis of piping layouts and to simulate the energy dissipated by the system as well as to more accurately evaluate its seismic vulnerability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
