Influence of adjusted models of plastic hinges in nonlinear behaviour of reinforced concrete buildings

• Influence of different plastic hinge models on the behaviour of RC structures.
• FEMA-356 model and two additional models developed by using empirical expressions.
• Simplified structures of two buildings have been nonlinearly analysed as examples.
• Similar results are obtained from the nonlinear static and dynamic analyses performed.
• A more precise model of elements in RC buildings located in seismic areas is achieved.

Among the procedures available for the seismic analysis of structures, pushover analysis is one of the most frequently used methods by structural engineers. An adequate modelling of the plastic hinges generated during the pushover analysis is crucial in order to obtain accurate results. Thus, the yielding and ultimate states of the cross-section must be defined in order to model the generalised force-deformation relation of plastic hinges. For this purpose, the use of empirical expressions that obtain the aforementioned states from the cross-section properties can prove beneficial.The main objective of this work is to study the influence of different plastic hinge models on the structural nonlinear behaviour of reinforced concrete structures. To that end, several nonlinear analyses have been performed with the software SAP2000®, considering the following plastic hinge models: (i) the model of FEMA-356 included in SAP2000®, and (ii) two additional models developed by some researchers by using empirical expressions calibrated with different experimental data. Simplified structures of two buildings have been used as examples.The results obtained show that plastic hinges modelled with empirical expressions can be used by structural engineers to more precisely model the behaviour of structural elements in ordinary reinforced concrete buildings located in seismic areas, and to compare with the results offered by the models included in seismic building design codes.