Past and recent seismic events have highlighted undesirable brittle failure in RC frame structures, indicating that a substantial damage may result from beam-column joints in non-seismically designed buildings. This paper presents a numerical investigation on exterior RC joints under seismic loading based on a macro-modelling approach, which employs the “scissors model” to schematize the shear behavior of the joint and the bond-slip of the longitudinal steel rebars at the beam-joint interface. A set of literature experimental tests have been used to develop a model for the estimate of the maximum shear strength and a new multilinear shear stress-strain law of the joint element. Cyclic analyses have been also performed by implementing the “pinching4” material parameters available in OpenSees, governing the hysteresis rules and pinching effect.
I passati e i recenti eventi sismici hanno evidenziato meccanismi di rottura fragili negli edifici in c.a., riconducibili spesso a danni localizzati nei nodi trave-colonna. Questa memoria illustra uno studio numerico su nodi esterni in c.a. soggetti ad azione sismica tramite un approccio di macro-modellazione, con l’uso dello “scissors model” per la riproduzione del comportamento a taglio del nodo e del fenomeno di sfilamento delle barre metalliche all’interfaccia nodo-trave. È stato selezionato un gruppo di test sperimentali di letteratura per mettere a punto un modello numerico in grado di stimare la massima resistenza a taglio e proporre una legge multilineare tensione-deformazione dell’elemento nodale. Sono state effettuate anche analisi cicliche implementando opportunamente i parametri del materiale “pinching4” disponibile in OpenSees, utili a definire le leggi di isteresi e l’effetto pinching.
Numerical modeling of the monotonic and cyclic behavior of exterior RC beam-column joints
Annalisa NapoliMembro del Collaboration Group
;Roberto Realfonzo
Membro del Collaboration Group
2022-01-01
Abstract
Past and recent seismic events have highlighted undesirable brittle failure in RC frame structures, indicating that a substantial damage may result from beam-column joints in non-seismically designed buildings. This paper presents a numerical investigation on exterior RC joints under seismic loading based on a macro-modelling approach, which employs the “scissors model” to schematize the shear behavior of the joint and the bond-slip of the longitudinal steel rebars at the beam-joint interface. A set of literature experimental tests have been used to develop a model for the estimate of the maximum shear strength and a new multilinear shear stress-strain law of the joint element. Cyclic analyses have been also performed by implementing the “pinching4” material parameters available in OpenSees, governing the hysteresis rules and pinching effect.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.