Numerical Investigation on the Performance of Exterior Beam-Column Joints Reinforced with Shape Memory Alloys

Upgraded design standards coupled with the damage caused by natural disasters have led to the development of smart materials with the potential to modernize current construction practices. This investigation proposes a nonlinear finite element (FE) model for evaluating the performance of beam-column joints (RC-BCJ) reinforced with shape memory alloys (SMA) and steel rebars. The model was validated based on accredited experimental data, followed by parametric analysis in ABAQUS to optimize the use of SMA bars for enhancing the seismic resistance of RC-BCJ without compromising their energy dissipation capacity. Parameters investigated include the (a) SMA-steel reinforcement ratio, (b) lengths of SMA bars, (c) elastic modulus of SMA, (d) compressive strength of concrete, and (e) axial load applied on the column. The finite element simulation results indicated that the model was capable of predicting the optimum length of SMA bars sufficient for relocating the plastic hinge away from the face of the column along the beam. Further, simulation results proved that the use of SMA bars in conjunction with steel reinforcement could be considered as an effective tool for enhancing the seismic performance of RC-BCJ joints. Among the parameters investigated, high-strength concrete was the most effective in improving joint resistance.

Automated summary

Upgraded design standards and natural disasters have driven the development of smart materials to modernize construction practices. This study presents a nonlinear finite element model for evaluating the performance of beam-column joints reinforced with shape memory alloys (SMA) and steel rebars. Through validation and parametric analysis, the optimal use of SMA bars to enhance seismic resistance without compromising energy dissipation capacity was determined. The simulation results showed that SMA bars, when used with steel reinforcement, effectively improved the seismic performance of the joints, with high-strength concrete being the most influential parameter.