Traditional retrofitting techniques for framed structures are based on widespread strengthening of the structure and/or on the introduction of additional, very stiff, structural members. Recently, innovative strategies for the passive control of structures have been studied and experimented, such as those based on the insertion of damped braces connecting two consecutive storeys of the building and incorporating suitable devices, purposely designed to dissipate a large amount of energy. The experimental and numerical results presented in this paper have been obtained considering a steel frame equipped with metallic hysteretic yielding dampers (HYDs). A shaking table test program was performed at the Structural Laboratory of the University of Basilicata within a wide research program, named JETPACS (“Joint Experimental Testing on Passive and semi-active Control Systems”) entirely founded by the Italian Department of Civil Protection. A 1/1.5 scaled, two storey, three-dimensional steel frame was seismically upgraded with HYDs. The HYDs, constituted of a low-carbon special- shaped steel plate, were designed with the performance objective of limiting the inter-storey drifts so that the frame yielding is prevented. Two design solutions were considered, assuming the same stiffness of the damped braces, but different values of both ductility demand and yield strength of the HYDs. Experimental outcomes proved the robustness of the HYD systems in well controlling seismic vibrations even for significant changes of the ductility factor and yield strength of the elastic-plastic devices.
Experimental and Numerical Behaviour of a Steel Frame Seismically Protected with Hysteretic Dampers Braces: the JET PACS Project.
PONZO, Felice Carlo;DI CESARE, ANTONIO;NIGRO, Domenico Salvatore;
2012-01-01
Abstract
Traditional retrofitting techniques for framed structures are based on widespread strengthening of the structure and/or on the introduction of additional, very stiff, structural members. Recently, innovative strategies for the passive control of structures have been studied and experimented, such as those based on the insertion of damped braces connecting two consecutive storeys of the building and incorporating suitable devices, purposely designed to dissipate a large amount of energy. The experimental and numerical results presented in this paper have been obtained considering a steel frame equipped with metallic hysteretic yielding dampers (HYDs). A shaking table test program was performed at the Structural Laboratory of the University of Basilicata within a wide research program, named JETPACS (“Joint Experimental Testing on Passive and semi-active Control Systems”) entirely founded by the Italian Department of Civil Protection. A 1/1.5 scaled, two storey, three-dimensional steel frame was seismically upgraded with HYDs. The HYDs, constituted of a low-carbon special- shaped steel plate, were designed with the performance objective of limiting the inter-storey drifts so that the frame yielding is prevented. Two design solutions were considered, assuming the same stiffness of the damped braces, but different values of both ductility demand and yield strength of the HYDs. Experimental outcomes proved the robustness of the HYD systems in well controlling seismic vibrations even for significant changes of the ductility factor and yield strength of the elastic-plastic devices.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
