Nowadays sophisticated numerical models allow to predict the earthquake response of reinforced concrete structures with enough accuracy. However, the prediction of the non-linear response, especially at large displacement demand, is still challenging due to the marked nonlinear phenomena of the structural components that are not easy to reproduce. This is even challenging when brittle failures govern the lateral response of the structural system. In order to characterize the seismic response of Reinforced Concrete (RC) buildings with flat slabs, often exhibiting a punching shear failure under lateral loads, an experimental program was carried out within the SlabSTRESS project. This paper presents the 3D fiber-based Finite Element model proposed to reproduce the seismic response of the two storey RC slab-frame prototype structure. It was developed in the OpenSees environment. Displacement-based elements were used to model RC columns and multi-layer nonlinear shell elements for the RC slabs. The response of the structure was analysed under combined gravity and seismic lateral loads. Two different gravity load configurations for each of the two considered seismic intensities (Serviceability and Ultimate Limit State) were considered. This modelling approach neglects the effect of punching shear, thus a check against the punching shear capacity of the slab was performed in post-processing the numerical results to identify the potential failures. The punching shear response of the first floor slab was predicted by using available literature formulations specifically developed for RC slabs without transverse reinforcements. Advantages and limitations of the proposed modelling approach are outlined and discussed with reference to the preliminary comparison with available experimental results. The maximum unbalanced bending moment and the column-to-slab rotation at the punching failure were characterized to identify the critical column-slab subassemblies.
An opensees fiber-based model for the blind prediction of the slabstress project
Del Vecchio C.Methodology
;Lignola G. P.;
2021-01-01
Abstract
Nowadays sophisticated numerical models allow to predict the earthquake response of reinforced concrete structures with enough accuracy. However, the prediction of the non-linear response, especially at large displacement demand, is still challenging due to the marked nonlinear phenomena of the structural components that are not easy to reproduce. This is even challenging when brittle failures govern the lateral response of the structural system. In order to characterize the seismic response of Reinforced Concrete (RC) buildings with flat slabs, often exhibiting a punching shear failure under lateral loads, an experimental program was carried out within the SlabSTRESS project. This paper presents the 3D fiber-based Finite Element model proposed to reproduce the seismic response of the two storey RC slab-frame prototype structure. It was developed in the OpenSees environment. Displacement-based elements were used to model RC columns and multi-layer nonlinear shell elements for the RC slabs. The response of the structure was analysed under combined gravity and seismic lateral loads. Two different gravity load configurations for each of the two considered seismic intensities (Serviceability and Ultimate Limit State) were considered. This modelling approach neglects the effect of punching shear, thus a check against the punching shear capacity of the slab was performed in post-processing the numerical results to identify the potential failures. The punching shear response of the first floor slab was predicted by using available literature formulations specifically developed for RC slabs without transverse reinforcements. Advantages and limitations of the proposed modelling approach are outlined and discussed with reference to the preliminary comparison with available experimental results. The maximum unbalanced bending moment and the column-to-slab rotation at the punching failure were characterized to identify the critical column-slab subassemblies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
