Behavior of Smart Reinforced Concrete Beam Column Joints by Using Shape Memory Alloy Reinforcement Under Repeated Loading

Using the super elastic materials in structures design is becoming very important   in the research field because of their rare ability in sensing the around effect and reacting against the mechanical and thermal react. The major intent in this research is designing smart concrete beam column joints reinforced by Shape Memory Alloy (SMA) bars. The suggested systems use the (super elastic) Pseudo Elastic (PE) react of the SMA as reinforcement after being subjected under monotonic and repeated load. The behaviors of systems were explored experimentally and by using finite element simulation.  In order to estimate load-displacement relationships of these specimens in this study, Analytical models were developed.  A comparison of the reinforced specimens by SMA was carried out and it contained that the variation in percentage of the SMA in flexural reinforcement (25%, 50%, 75%) of the total flexural reinforcement by using this substitution get a clear effect on the failure load and the ultimate displacement of the specimens with these different ratios. The Finite Element models were developed by using the software ABAQUS. The models have been checked with the experimental results in the load-displacement terms in the top reinforcement. The models showed reasonable response.  Where the ultimate load decreased by using SMA bars in (25%, 50%, 75% ) percentage of total flexural reinforcement about (50.51%, 28.32%, 38.15%) respectively,  in case of static loading and (20.7%, 10.7%, 9.3%) respectively  in case of repeated loading, and the deflection is increasing by using SMA in (25%, 50%, 75% ) percentage of total flexural reinforcement about (1.2%, 8.4%, 0.36%) respectively,  in case of static loading and (9.6%, 5.28%, 10.9%) respectively  in case of repeated loading