FE MODELING AND SEISMIC PERFORMANCE EVALUATION OF HYBRID SMA-STEEL RC BEAM-COLUMN JOINTS

Abstract

EXCESSIVE RESIDUAL DISPLACEMENTS OF BUILDINGS DURING EARTHQUAKES HAVE BEEN FOUND AS THE MAJOR CAUSE OF THE FAILURE OF STRUCTURES. THE APPLICATION OF SUPERELASTIC SHAPE MEMORY ALLOY REBARS AT THE PLASTIC HINGE REGION OF REINFORCED CONCRETE BEAM-COLUMN JOINTS (SESMA-BCJS) CAN LEAD TO THE ELIMINATION OF THE SEISMIC RESIDUAL DEFORMATION. SUCH SELF-CENTERING STRUCTURES MAINTAIN THEIR REUSABILITY EVEN AFTER SEVERE EARTHQUAKES. THIS RESEARCH PROPOSES A SIMPLE - YET PRACTICAL - TECHNIQUE FOR MORE ACCURATE FE MODELING OF SESMA-BCJS USING VECTOR2 SOFTWARE. BOTH MATERIAL AND GEOMETRIC NONLINEARITY ARE CONSIDERED. EFFICIENCY AND VERSATILITY OF THE MODELING APPROACH ARE VERIFIED AGAINST A NUMBER OF TEST RESULTS AT BOTH THE MATERIAL AND STRUCTURAL LEVELS. ACCORDING TO THE RESULTS, THE ADOPTED MODELING APPROACH CAN BE RELIABLY USED FOR THE PREDICTION OF THE CYCLIC RESPONSE OF HYBRID SESMA-BCJS UNDER CHANGING VARIOUS DESIGN PARAMETERS THAT ARE BEYOND THE SCOPE OF THE EXPERIMENTAL TESTS. FURTHERMORE, USING THE CALIBRATED MODEL, A COMPREHENSIVE SEISMIC PARAMETRIC STUDY IS CONDUCTED TO INVESTIGATE THE INFLUENCE OF VARIOUS DESIGN PARAMETERS ON THE SEISMIC PERFORMANCE OF SESMA-BCJS. FINALLY, A NEW FE-BASED SESMA-BCJ WITH LOWER COST AND HIGHER SEISMIC PERFORMANCE THAN NITI-BASED BCJS IS INTRODUCED AND NUMERICALLY INVESTIGATED.