الخلاصة:
The beam-column joints play an important role in the structures where the functions of connection shortage by transport the forces like shear, moment, and torsion from the beam to the column. So, this study represents an attempt to investigate the performance and the effect of limited cycles of repeated load on the strength of the exterior beam-column joint core. Therefore, 34 specimens have been investigated by using a numerical analysis that used the finite element method. To simulate these specimens, the concrete damage plasticity model was used to define the concrete materials and the nonlinear isotropic/kinematic (combined) hardening model for steel material definition. These models are involved in the ABAQUS software package, version 2020. This study involves key parametric studies on beam-column joints, which are summarized as changing the ratio of shear reinforcement of the joint core in addition to using two types of shear reinforcement. This study also includes the effect of flexural reinforcement of the beam as well as the beam’s shear reinforcement effect on the strength of the beam-column joint. To calibrate the software to simulate a realistic result, three specimens have been used, which have been tested in previous studies. It has been found that this numerical model accurately predicts the experimental response under limited cycles of repeated loading. The ultimate load from modelling was compared with the experiment once, having a difference of less than 10% and the ultimate displacement having a difference of less than 11%. It has been found that increasing the ratio of the joint’s shear reinforcement to double has no significant effect on the ultimate load. Otherwise, decreasing it to half leads to a decrease in the ultimate load compared with a specimen that is designed according to ASCE352-02R. This study has studied the effectiveness of increasing the shear reinforcement by adding an x-shape reinforcement. Also, the flexural reinforcement of the beam has found it has increased the ultimate load capacity by 48% Where the ratio of flexural reinforcement increased to 1.8%, the load bearing capacity was enhanced.
