FE Modeling and Seismic Performance Evaluation of Hybrid SMA-Steel RC Beam-Column Joints

Abstract

Severe permanent deformations of buildings during earthquakes have been found as one of the major causes of the instability and 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 eliminate the seismic residual deformations. Such self-centering structures can maintain their reusability even after severe earthquakes. This research proposes a simple -yet practical -technique for more accurate modeling of SESMA-BCJs using VecTor2 software. Both material and geometric nonlinearity were considered. Efficiency and versatility of the modeling approach were verified against a number of test results at both 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 which are beyond the scope of the experimental tests. Furthermore, using the calibrated model, a comprehensive seismic parametric study was conducted to investigate the influence of various design parameters on the seismic performance of SESMA-BCJs. Finally, a new Fe-based SESMA-BCJ with a lower amount of SESMA and higher seismic performance than NiTi-based BCJs was introduced and numerically investigated.

Implementation of Modified Compression Field Theory to Simulate the Behavior of Fiber-Reinforced Polymer Shear-Strengthened Reinforced Concrete Beams under Monotonic Loading

“…In addition, they anticipated a pattern for the load-deflection relationship of RC elements subjected to in-plane normal and shear stresses [12,14,22]. In the MCFT theory, the cracked concrete is treated as an orthotropic material, and the smeared rotating crack approach is implemented to achieve compatible crack patterns with those detected in many RC members [24][25][26]. Additionally, the smeared rotating cracks are automatically redirected without any restraint to be aligned with the direction of the principal concrete compressive stress field [13,27].…”

“…Buildings 2023, 13, x FOR PEER REVIEW 8 of 24 tensile strength, is simulated by employing the Modified Bentz model[25,[35][36][37]. The tension stiffening is a significantly required feature to capture the load-deformation relationship.…”