Simplified mechanical models for critical regions in RC frame systems

A mechanical model for the representation of the structural performance of the critical regions of reinforced concrete (RC) frame systems is provided and calibrated using the results of experimental tests on full-scale joints realized using different reinforcing steel grades. The proposed mechanical model describes the behaviour of the RC section along the plastic hinge length through a certain number of concrete and steel components, modelled as trusses located along the section's height. Kinematic constraints are introduced to simulate the rigid section performance, bond-slip springs are used to reproduce the lack of perfect bond.