Nonlinear Modeling of RC Substandard Beam–Column Joints for Building Response Analysis in Support of Seismic Risk Assessment and Loss Estimation

The paper discusses how joint damage and deterioration affect the seismic response of existing reinforced concrete frames with sub-standard beam–column joints. available simplified modeling techniques are critically reviewed to propose a robust, yet computationally efficient, technique for simulating nonlinear behavior substandard Improvements over models include simulation cyclic stiffness strength, as well pinching in hysteretic response, implemented considering deteriorating rule. A fiber-section forced-based inelastic element is developed, improved material fixed-end rotation due bond failure, rebars-slip, extension, simulate pre-cracked members. For assessment exterior joints, model developed validated through full-scale quasi-static test performed on T-joint connection. proposed allows structural performance risk while accounting true mechanisms at An five-story RC frame revealed that activation shear mechanism increases chord demand connecting beam members by up 85%, 62% (mean drift) 89% + 1.std.) lower floors when determining inter-story drift demand, collapse probability structures subjected design base ground motions increased from 4.20% 29.20%.